Government figures showed 2,948 confirmed cases of coronavirus on Monday, following the 2,988 recorded on Sunday. A week earlier, the combined UK daily total was less than 1,300.

Matt Hancock, the health secretary, said younger people, especially those in better-off areas, should remain observant of distancing rules if the UK was to avoid a wider return of the virus, as seen in Spain and France.

In the seven days to 7 September, there were 21.3 cases per 100,000, and a total of 14,227.

This means the UK’s weekly rate of new coronavirus cases has now risen above 20 per 100,000, the threshold at which the government considers imposing quarantine restrictions on travellers arriving from countries abroad.

The rate is up from 13.9 per 100,000 in the seven days to 31 August.

While local lockdowns have been mainly concentrated in poorer areas, Hancock said this had now changed. “The recent increase we have seen in the last few days is more broadly spread,” he said. “It’s actually among more affluent younger people where we have seen the rise.”

After almost 3,000 people tested positive for Covid-19 on Sunday, a 65% rise in a single day and the highest daily total since May, Hancock said the UK could soon start to see a renewed rise in hospital admissions.

Speaking on a phone-in with LBC radio, Hancock said much of the rise was among younger people, and it was vitally important for them to take measures to avoid spreading the virus. “It’s concerning because we’ve seen a rise in cases in France, in Spain, in some other countries across Europe, and nobody wants to see a second wave here,” he said.

“The rise in the number of cases we’ve seen over the last few days is largely among younger people – under-25s, especially between 17 and 21. The message to all your younger listeners is that even though you’re at lower risk of dying from Covid if you’re under 25, you can still have really serious symptoms and consequences.”

While the mortality rate among young people was lower, Hancock said, they could still be susceptible to debilitating long-term symptoms. “Also, you can infect other people. And this argument that we’ve seen that you don’t need to worry about a rise in cases because it’s young people, and they don’t die – firstly they can get very, very ill, and secondly, inevitably, it leads to older people catching it from them.”

Hancock dismissed the idea that the increase in cases was largely down to more testing, saying the figure for so-called test positivity – the proportion of tests that show someone does have Covid-19 – was also going up.

The point was reiterated by Downing Street, as Boris Johnson’s spokesman urged people to act. “The rise in the number of cases is concerning, and we’re seeing them predominantly among young people,” he said. “Generally, a rise in cases among younger people leads to a rise in cases across the population as a whole. That’s why it’s so important that people maintain social distancing and don’t allow this illness to infect older generations.”

Answering questions from listeners, Hancock played down the potential impact of medical supplies if the UK leaves the EU with no long-term trade deal, saying this would not be nearly as bad as if there had been no initial deal.

Hancock was questioned after it emerged that Johnson was drawing up legislation that would override the Brexit withdrawal agreement on Northern Ireland, threatening to collapse talks with the EU.

“We already have a deal. The question is whether we can land a long-term future trade agreement,” Hancock said. Asked if he could guarantee no disruption to medical supplies, he said: “I’m comfortable that we’ve done the work that is needed.”

Speaking to one Nottingham-based listener, Hancock accepted that there had been difficulties in getting people Covid tests near them, after the man said he had been sent for a test in Dundee, nearly 350 miles away.

This had happened 10 days ago, the man said. Hancock replied that the system had since improved. “We’ve changed that now so that people get offered tests within 75 miles, which is still quite a hike, if you need to.”

He added: “The good news is that the vast majority of people get offered access to a test at their local testing centre, and it’s turned around very rapidly – the vast majority of results come the next day. But there have been problems and we’re increasing capacity.”

Boris Johnson is facing fresh warnings that his planning overhaul risks denting his commitment to “level up” the country, amid mounting Tory anxiety over the proposals.

Conservative MPs have already raised concerns directly with the prime minister about planning reforms designed to push through the construction of more than 300,000 houses a year. MPs have focused on the model used to allocate new housing targets for each area, with Tories warning it will lead to houses being built in their shire heartlands, rather than the metropolitan centres.

However, there are new warnings that other parts of the plan could end up hurting the government’s central election pledge to “level up” more deprived parts of the country, where the Tories found new supporters at the last election.

Under the proposals, funds for new infrastructure and social housing would be raised from a nationally fixed levy. The levy, handed to local councils, would be applied to the predicted market value of a building development once completed.

Planning experts warned that the huge disparity in the market value of developments between London, the south-east and the rest of the country meant the system could end up raising most funds for areas that already had good local amenities.

Setting the rate nationally could mean developers are attracted to more profitable schemes in the south-east than elsewhere. An initial analysis by some of Britain’s leading housing academics warned there were “consequences for regional imbalances”.

“Since the values of completed developments are much greater in London and the southern regions of England than elsewhere, [councils] in these areas will have greater capacity to benefit and fund their infrastructure needs, including schools, doctors’ surgeries, highways … in addition to securing new affordable homes,” write professors Tony Crook and John Henneberry from the University of Sheffield and Christine Whitehead from the London School of Economics. “All of these will be more difficult to secure elsewhere.”

There are calls for the levy to be set locally instead. Neil O’Brien, Tory MP for Harborough, Oadby and Wigston, said this was preferable “because what can be raised varies so much that one size is unlikely to fit all”.

Christopher Pincher, the housing minister, writing on the Conservative Home website, has tried to calm MPs’ fears that the model used to allocate housing needs across the country will hit Tory seats. He said the initial calculations were only “the first step”.

The Ministry of Housing, Communities and Local Government was contacted for comment, but had not done so by the point of publication.

Chloe Gray, who lives in one, is desperate to leave. She has nowhere to put a wardrobe and has a single cupboard for food. The 20-year-old, who is on universal credit, said: “I have been here for about a year now but I will be moving out in October as it is just too small. I moved here from home because I needed my independence and this was all I could afford. It really does feel like living in a pod.”

Chloe pays £525 a month including bills to rent the property, which works out at about £33 a square metre, making it more expensive to rent than a house in Islington, north London.

The block was designed by a local firm specialising in redevelopments, Concept Design & Planning, although it does not feature among the projects showcased on its website. The firm boasts of having a “proven track record in gaining planning permission across the south coast”.

Next door to the flats, Robert Webb, 43, has been running a barber’s for 21 years. His parents were among locals who opposed the development, but “everyone’s complaints just got rejected”, he says.

“The flats are tiny,” he added. “I have a friend who lives not far away in the New Forest, and the kennel for his two dogs is bigger than these flats next door.”

Since 2013 PDR has let developers bypass the requirement to apply for planning permission when turning office blocks into flats. This was expanded to include shops, bookmakers and launderettes in 2016, before fast-food outlets were added last year.

Government data suggests 60,399 homes have been created. Developers may not transform the outside appearance but have automatic rights to change how the property is used.

In July Robert Jenrick, the housing secretary, announced that PDR would be expanded further to let developers demolish vacant buildings without full planning permission so they can be “quickly repurposed to help revive our high streets and town centres”.

A report published the same month, commissioned by the government and carried out by University College London and Liverpool University, suggested PDR is leading to “slum housing” and poses a risk to the “health and wellbeing of occupiers”.

The Royal Institute of British Architects has branded the decision to extend the policy “disgraceful”.

PDR flats are not bound by the minimum space standard, which says studios have to be at least 37 square metres. The government report surveyed more than 2,800 flats and found three-quarters had windows on just one side; 10 had no windows at all. A link between natural light and mental health is well established.

A two-storey building at 187 Whitehall Road in Bristol housed a barber called Super Tonic for several years. However, plans by a local architecture firm, We Are Not Architects, were approved in June to convert the premises into five small flats. The building is squeezed between a shop and a house, so the only natural light in the rear ground-floor flat will come from two windows facing a narrow alleyway.

Developers must now show that PDR flats have “adequate natural light in all habitable rooms”, yet no minimum window size is given and planning officers are “expected to exercise their planning judgment” when approving homes, leaving the rules open to interpretation.

In Croydon, south London, an application was approved on August 7 to convert a 93 square metre basement owned by a financial services company into three studio flats, with daylight entering only through two light wells above.

Experts say Covid-19 has accelerated the residential takeover of the high street. Jamie Lockerbie, a planning partner at the law firm Pinsent Masons, said: “If you own a retail space and the tenants have gone bust — as many have during the pandemic — then, instead of leaving it empty, many will be persuaded to turn it into flats.”

A survey of five councils found 55 successful applications to convert shops into flats since last September, with the majority — 35 — happening after Britain went into lockdown on March 23. The resulting developments across Bristol, Southampton, Leicester, Birmingham and Croydon will lead to 132 new homes, suggesting that there may be thousands of new high-street flats being constructed across the country.

Andrew Boff, a Conservative London assembly member, said: “The Tory party simply won’t be thanked for building crappy homes.”

Tom Copley, London’s deputy mayor for housing and residential development, added: “The solution to the housing crisis is not to create new slums out of old offices and shops, but the delivery of high-quality, well-planned, affordable homes. If lockdown and the Covid-19 pandemic should teach us anything about housing, it is the importance of minimum space standards, both internal and external.”

The Ministry of Housing, Communities and Local Government dismissed the findings as “misleading and unfounded”, adding that PDRs “make an important contribution to building the homes our country needs and are crucial to helping our economy recover from the pandemic by supporting our high streets to adapt”.

The document, leaked to the Observer, and marked “official sensitive”, suggests the national lockdown in these parts of the north of England had little effect in reducing the level of infections, and that in such communities it is now firmly established.

The analysis, prepared for local government leaders and health experts, relates specifically to the north-west, where several local lockdowns have recently been put in place following spikes in numbers. But it suggests that the lessons could be applied nationally. Based on detailed analysis of case numbers in different local areas, the study builds links between the highest concentrations of Covid-19 and issues of deprivation, poor and crowded accommodation and ethnicity.

Produced in the last few weeks and containing data up to August, it states: “The overall analysis suggests Bolton, Manchester, Oldham and Rochdale never really left the epidemic phase – and that nine of the 10 boroughs [of Greater Manchester] are currently experiencing an epidemic phase.”

The five worst-hit areas are all currently in the north-west. Bolton had 98.1 cases per 100,000 people last week, with 63.2 in Bradford, 56.8 in Blackburn and Darwen, 53.6 in Oldham and 46.7 in Salford. Milton Keynes, by comparison, had 5.9 per 100,000, and it was 5.2 in Kent and 3.2 in Southampton.

Comparing other English regions, the study says: “Each region has experienced its own epidemic journey with the north peaking later and the NW [north-west], Y&H [Yorkshire and Humber] and EM [East Midlands] failing to return to a near zero Covid status even during lockdown, unlike the other regions which have been able to return to a near pre-Covid state.”

It also questions, under a heading marked for “discussion”, why anyone should expect fresh local lockdowns to work in these areas now: “If we accept the premise that in some areas the infection is now endemic – how does this change our strategy? If these areas were not able to attain near zero-Covid status during full lockdown, how realistic is it that we can expect current restriction escalations to work?”

The comments point to friction between Public Health England and the government over the strategy to tackle local outbreaks as a potential second wave of Covid-19 threatens.

Last night, Gabriel Scally, visiting professor of public health at the University of Bristol and a member of the independent Sage committee, described the findings of the leaked report as “extremely alarming” after being shown them by the Observer.

“The only way forward is to build a system which provides much better, more locally tailored responses,” Scally said. “There is no integrated find, test, trace, isolate and support system at the moment. The data on housing is extraordinarily important. Overcrowded households are part of public health history. Housing conditions are so important and always have been, whether it was for cholera or tuberculosis or Covid-19.

“Doing something about housing conditions for someone who has an active infection is extremely important and it is not something that can be handled by a call centre run by a commercial company hundreds of miles away.”

Scally said that helping people to isolate by giving financial support was also crucial: “Taking two weeks off if you are on a zero-hours contract is not an option for people.”

Matthew Ashton, director of public health at Liverpool city council, said on seeing the study: “This report shows a strong link between our most deprived areas, our BAME communities and poor housing communities, and that can lead to the virus becoming endemic. I absolutely agree with that. But I think it is also more complicated in that there are different types of outbreaks and different types of ways in which the virus could become endemic, such as opening the night-time economy and young people getting the virus asymptomatically and then passing it on.”

Last night, amid continuing confusion over rules on quarantining when returning to the UK, Labour called for a “rapid review” to restore public confidence. In a letter to the home secretary, Labour is urging the government to consider introducing a “robust testing regime in airports” that could help to safely minimise the need for 14-day quarantine.

There have been more than 340,000 confirmed cases of coronavirus so far in the UK, and more than 40,000 people have died, according to government figures.

Local lockdowns are now being implemented or relaxed across the country in response to surges. The most recent have seen Norfolk, Rossendale and Northampton added as “areas of enhanced support”, meaning the government will work with local authorities to provide additional resources – such as testing or contact tracing – to help bring infection numbers down.

Improvements in Newark and Sherwood in Nottinghamshire, Slough in Berkshire and Wakefield. West Yorkshire, mean they have been removed from the watchlist. Restrictions already in place in parts of Greater Manchester, Lancashire and West Yorkshire have been eased.

In Scotland, restrictions on visiting other households were reintroduced this week in Glasgow, West Dunbartonshire and East Renfrewshire.

The Observer has been told that Johnson was so furious after last Wednesday’s prime minister’s questions – where he was asked to withdraw comments he made about the Labour leader and the IRA by the Speaker, Lindsay Hoyle – that he turned on his staff for leaving him under-prepared, and asked them to come up with more attack lines on the Labour leader’s career as a lawyer.

“He was furious,” said a well-placed source. “He told his team and people at CCHQ [Conservative campaign headquarters] that he wanted them to go after Starmer’s legal record and double down on the attacks on him.”

Last week’s Commons row erupted after Starmer pressed Johnson at PMQs over the recent exams fiasco and his party’s succession of policy U-turns.

Johnson attempted to turn the tables, suddenly suggesting the Labour leader had somehow been sympathetic to the IRA because he had worked under Jeremy Corbyn. “This is a leader of the opposition who supported an IRA-condoning politician,” said Johnson, to the bemusement of MPs on all sides of the house.

An angry Starmer pointed out he had in fact spent five years of his legal career prosecuting IRA terrorists and working with the intelligence services to bring terrorists to justice. Despite Hoyle’s request for Johnson to apologise he refused to do so.

A Labour source said: “If Boris Johnson wants to have a debate with Keir about past careers then bring it on. While Keir was a human rights lawyer or director of public prosecutions Johnson was being sacked for lying.”

Last night Downing Street claimed it was “not true” that Johnson had blamed his staff for his performance at PMQs or that he had said to anyone that he wanted to prepare more attacks on Starmer over his time as a lawyer.

But increasingly his and the government’s performances are causing alarm among Tory MPs, and disquiet in Whitehall.

Some senior Conservatives are beginning to worry that Starmer is regularly outperforming the prime minister at the weekly confrontation on Wednesdays. A senior Tory MP said: “It is the issue of competence that we worry about against Starmer.”

As the country faces a possible Covid-19 second wave and the prospect of an economically damaging no-deal Brexit, there is evidence that the wider Tory party is losing faith in Johnson’s ability to lead them against Starmer – and signs that the chancellor Rishi Sunak has become the new favourite of the Conservative grassroots.

According to the latest survey of Tory members by ConservativeHome, the website for party activists, Johnson is now in the bottom third of cabinet ministers in the satisfaction ratings – having been the runaway leader nine months ago.

In December 2019, shortly after the last general election, Johnson topped the net satisfaction ratings with a score of plus 92.5%, while Sunak was fourth on plus 78.5%.

Now Johnson has slumped to 19th place, below Baroness Evans, the leader of the House of Lords, with a rating of plus 24.6%. Sunak meanwhile is out in front on plus 82.5%.

Patrick Stevens, a former colleague of Starmer at the crown prosecution service who was head of its international division, said the Labour leader’s legal career was beyond reproach.

“I worked with Keir Starmer at close quarters for five years. His work with the CPS’s world-class counter-terrorism division – the most serious and sensitive the service faced – was unwavering.

“He was equally committed to the CPS playing its part internationally in the UK government’s national security strategies, leading the CPS to engage in some of the most difficult jurisdictions around the world.

“His efforts went way beyond just doing the job; personally I haven’t met anyone more committed to the rights of victims and witnesses and the protection of the public.”

On Saturday ministers were facing new difficulties in persuading civil servants to “get back to work” as soon as possible.

The government says it wants 80% of civil servants to be able to attend their usual workplaces at least once a week by the end of the month. But unions have described the government’s attitude as outdated.

“Disruption” has become the mantra. “Change” and “reform” are thought good in themselves. Apple carts must be upset, established rules and structures of governance “challenged”, trusted brands trashed. There’s a fine line between usefully critical vigilance over institutions we cherish, and a habit of scorn towards the organisations and systems that time has shaped and which, over time, have shaped us. I fear we’re crossing that line.

Take Roper’s frustration with being tripped up by the law as he chases the Devil. A case can be made for trimming back legal aid, or resisting the advance of the Supreme Court and judicial review as brakes on the exuberance of politicians. But if we don’t start from the massive respect for the rule of law that (though she was often impatient) Margaret Thatcher always showed, then we risk disaster. Few can have missed the dog-whistles of Conservative politicians all but condemning judges as enemies of the people.

Yes, Minister was Thatcher’s favourite TV satire. She found the Sir Humphreys of the Whitehall mandarinate maddening, as would any prime minister restless for action. But there was also deference: a clear understanding that Westminster and Whitehall are great and permanent estates. I don’t hear that respect today, as politicians and their media claque routinely refer to the civil service as some kind of fifth column to be subdued, broken.

I detect a similarly threatening attitude to the BBC. God knows the corporation can infuriate but when we’re cross, it should be because we love and feel proud of a corporation that’s a model to the whole world’s media.

The same is true of the fabric of our planning laws and procedures. Labour’s 1947 Town and Country Planning Act laid the foundations for the way we shape our urban and rural landscapes, and I return from driving across the Continent with a renewed sense of what Britain has achieved. Of course reviews and reform are needed but voices in government today almost hint that all planning constraint is regrettable. I know from living in a national park that constraint can be life-enhancing.

Then there’s the constitution. Our Union faces appalling strains already, and to talk as if the casual loss of Scotland or Northern Ireland would be just a bit of collateral damage in the Brexit wars is horrifying. At the other end of the scale are institutions outside government but which government should see as part of our national life. British Airways was bound to take a hit from the pandemic but are we just going to shrug and let it go? The National Trust has been badly shaken by outside attack.

I must not blame politicians alone. I could include newspaper columnists. We love tilting at things. But the critics of our institutions ought to be terriers yapping at the heels of lumbering giants. Often it now feels as though the giants have fallen and it is the jugular for which mastiffs are aiming. Likewise the Black Lives Matter movement should aim to correct and critique, not destroy, and should never forget what a great, free and civilised country we live in: here, and in the United States too. The national motto of the Republic of Colombia is Libertad y Orden — Liberty, but Order too. At its heart must stand institutions, procedures, structures and — yes — bureaucracy. These should not be dirty words.

I’ve mentioned the confusion, bordering on self-dislike, in private and public institutions. Some of this must be traceable to social media. In the past complaints were stopped at the door. There were filters. Now unvarnished harangues skip the post box and the PA and are delivered straight into the chief executive’s hand. In my experience, people at the top are unprofessionally neuralgic about complaints that come to them direct, forgetting that silence from most may mean most are content. Chief executives’ phones, like ours, make the professional personal. By letting so much coalesce in one device, we have stripped back barriers that gave pause for thought, or let tempers cool, or took away the private edge. The mob isn’t at the chief executive’s door. It’s just in his pocket. Public-facing executives, in national institutions and private-sector corporations alike, take fright and panic.

Great newspapers — institutions too — are not immune to this confidence-sapping virus. Some risk ancient reputations in the search for online clicks, as has the BBC news website. Dispensing with editorial judgment in pursuit of mere traffic betrays an institution’s failure of confidence in us, its customers, whom in a less jittery age it thought it knew. Media companies lose their nerve, deferring to what the data says, wrongly, about us. Collapse in internal self-belief is as much a cause of shakiness in our institutions as an external attack.

I’m far from saying that reformist assaults upon our institutions haven’t forever been with us, or shouldn’t be. We will always rail against committees, protocol and fustiness, the stick-in-the-muds and bells-and-whistles of venerable institutions. This is healthy. But if a balance is to be struck between critical vigilance and a near-anarchic destructiveness, then there needs to be pushback. The party of which I was a member used to provide it. It was called the Conservative Party. We knew the value of dragging our feet. Today, I almost feel the Tories are on the side of the wreckers.

There’s a war on. The pandemic threatens. Our economy staggers. Unemployment rises. The whole international order is under siege from the Putins, Xis and Trumps of this world. Not disruption but protection, not upheaval but steadiness, not the sweeping aside but continuity: this should be the call: the call of the known, the tried and tested, the familiar. Conservatives, of all people, should hear it.

For his part Mr Trump regarded Mr Johnson as a “kindred spirit”, according to the former ambassador. Lord Darroch’s most damaging claim is that Mr Johnson helped to force him out of his job at a time when he was under attack from Mr Trump, whom the envoy had termed “inept” in a diplomatic cable.

Mr Johnson, then running for the Conservative leadership, repeatedly refused to say that he would keep him in post during a TV debate between rival candidates on July 9, 2019, in contrast to Jeremy Hunt, his opponent.

The civil servant, who resigned the following day, told Mr Johnson that he was in part to blame after the politician called to question why he had quit.

In an interview with The Times Magazine Lord Darroch says: “He sounded just like Boris Johnson sounds — starting and then restarting sentences. Very Boris. He said, ‘But why did you resign? Wouldn’t it all have blown over after a few weeks?’ ” In answer to Mr Johnson’s question as to whether the resignation was his fault, he told him that “in part it was”.

Lord Darroch says that Mr Johnson was “intrigued by Trump’s limited vocabulary, the simplicity of the messaging, the disdain for political correctness, the sometimes incendiary imagery, and the at best intermittent relationship with facts and the truth”.

Asked if Mr Johnson has modelled himself on the US president, the former ambassador said: “If you go back through the current prime minister’s history, he’s often said quite striking things. And he never apologises. So, Boris might have done this anyway, but certainly, having watched Trump in action, he wouldn’t have been put off.”

Mr Johnson was “warm” towards Steve Bannon during visits to Washington as foreign secretary, exchanging numbers and emails with the aide, who left Mr Trump’s White House and faces trial on fraud charges, which he denies.

Lord Darroch relates that on one visit Mr Johnson’s then press aide came back in high spirits and, after a problem with his key, attempted to break into the ambassador’s residence via a flat roof. He was spotted on CCTV, apprehended by security and escorted to his room, where he vomited on the carpet.

Lord Darroch, who took his seat in the Lords as a crossbencher in January, was national security adviser in 2012-15. Sir Mark Sedwill, a successor in the role, has left government along with several other senior civil servants after “a sort of trial by briefing to newspapers”, he says.

“Civil servants can’t go out and say what they think, so it’s a free hit for those doing the briefing. I believe it could be stopped if senior ministers were to say, ‘You have to stop doing this.’ With all the challenges in this period in history — Brexit on top of the virus on top of other stuff — is civil service reform really the biggest priority? We’ll see how it looks in three or four years.”

The screens, which in time will display data-tracking progress against key challenges such as coronavirus, were showing a Powerpoint presentation of government priorities.

Further down Whitehall in the Treasury, one metric above all is flashing red — Britain’s ever-growing mountain of debt. Government borrowing has ballooned over the past few months to pay for an additional £190 billion spending since March.

While millions of diners were Eating Out to Help Out last month, the man picking up some of the bill was wondering how to pay. Rishi Sunak, the chancellor, commissioned work on a slew of tax rises but he and his team were aghast to see their deliberations splashed across the newspapers as MPs were about to return to parliament.

Seven major tax rises were modelled over the summer, including increases to capital gains tax, corporation tax, fuel duty and national insurance contributions for the self-employed. Cuts to pension tax relief for high earners are being mooted along with a simplification of inheritance tax rules.

In normal times, any one of the tax changes would be deemed politically toxic, as previous chancellors such as George Osborne found to their cost.

Without context or other explanations many, if not all, of the rises looked unappealing, including to Mr Johnson. The extent to which the prime minister is prepared to increase taxes in the budget this autumn remains unclear but some of his cabinet believe that he is determined to resist his chancellor.

“It’s not going to happen,” one senior ally said. “It’s the wrong solution. It goes against fundamental Tory principles. It’s not what Downing Street wants to do. The prime minister is not into it at all. This is a Treasury position, not a No 10 position. These briefings are all about softening up No 10.”

Details of the Treasury’s proposals infuriated some cabinet ministers.

“If you raise taxes at this stage you will choke off the economic growth that will pay off the debt in the long term,” one said. “There’s no support for this on the back benches. If we wanted Jeremy Corbyn and his tax rises we would have voted for him. We didn’t.”

Alok Sharma, the business secretary, and Oliver Dowden, the culture secretary, are said to be more accepting of the idea of tax rises. One cabinet minister said: “The issue will be that because Boris is not Mr Austerity, where are we going to get the money? I’d be absolutely against direct tax rises but we do have to look at indirect taxes. At the moment we’re addicted to the low cost of borrowing and it looks like that is going to continue for some time.”

There is a continuing debate around the Tory manifesto pledges, particularly the pensions triple lock. Under the mechanism, the state pension rises in line with wages, inflation or 2.5 per cent, whichever is higher.

Mr Sunak is understood to be pushing for the lock to be suspended next year to ditch the 2.5 per cent element.

This would save the Treasury £2 billion a year and avoid a significant rise in state pensions at a time when wages are expected to stagnate. Mr Johnson is said to hate the idea of abandoning a manifesto pledge.

Of the tax rises under consideration, the Treasury is understood to believe that pensions tax relief is the most ripe for reform. Higher earners now get tax relief at their marginal rate of 40 per cent when making pensions contributions, while lower earners have relief of just 20 per cent. “It’s inherently unfair,” one Treasury source said. “Why should the rich get such a huge benefit compared to those on lower earnings?”

Mr Sunak is understood to be considering introducing a flat rate of relief for all saving into their pensions. Sajid Javid, Mr Sunak’s predecessor, considered adopting a flat rate of 30 per cent. The move would provide a boost to lower earners saving into their pensions while cutting relief for higher earners.

Treasury modelling suggests that it would save the government £3 billion to £4 billion. Mr Sunak is considering a flat rate of tax relief of 20 per cent, saving about £10 billion a year. While the savings may be significant, introducing the measures would be complex and require Revenue & Customs to devise a new system, taking up to five years to implement. Whatever the private tensions, the prime minister and chancellor stood together as they addressed MPs on Wednesday. “If we don’t approach the next election with there being some clear blue water on spending, borrowing and of course, tax, then we will have removed one of the most important reasons that people vote Conservative,” Mr Sunak told a meeting of last year’s intake of Tory MPs. “If that’s what the British people believe in — that none of this stuff matters, sound finances don’t matter — then they would have voted Labour at the last election. But they didn’t. So it is important we set up that distinction, you can’t just show up three months before the next election and say this stuff is important. You’ve got to prove it.”

Mr Johnson warned the new intake that things were going to get worse before they got better — widely interpreted as an acknowledgement that the budget would be politically painful.

Mr Sunak is said to be determined that the budget proves to the markets that he is prepared to set public finances on a course towards sustainability.

Downing Street sources said that Mr Johnson and Mr Sunak were in “lock step” over plans for the budget. The vehemence of the response to some of the proposals caught Mr Sunak off guard, however. Rises to fuel duty are now almost out of the question. He is sympathetic, also, to the argument that faced with Brexit uncertainty a rise in corporation tax may be best postponed.

Meanwhile, Mr Cummings presses ahead with his rewiring efforts behind a bank of desks that includes his data supremo, Ben Warner, and officials.

The key figure apart from Mr Cummings is Munira Mirza, the head of the policy unit. Also in the room is the prime minister’s implementation unit and the No 10 legislation team.

Insiders say that Mr Johnson prefers to remain in No 10, along with Martin Reynolds, his principal private secretary. Lord Frost’s Brexit unit has not moved to mission control, nor has Mr Sunak’s team. Sir Ed Lister, the chief strategic adviser, is also absent.

“It’s like a sort of data boy’s frat house,” one official said after visiting Room 38. “Dom sits there with the people he thinks are clever enough to be there. It’s like that film about Facebook, The Social Network. You know, where they sit around in a Harvard dorm trying to build some software. Except they’re trying to run a country.”

Simon Case, the new cabinet secretary, retains an office almost equidistant from both power centres.

Government statistics show that 96 new cases have been confirmed across the region in the past seven days in both pillar 1 data from tests carried out by the NHS and pillar 2 data from commercial partners, compared to 102 new cases confirmed last week.