A study by Loughborough University suggested three quarters of lone parent families had earnings too low to meet their minimum needs – up by 65% since the financial crisis in 2008.

And the number of single women in their early 60s – a group affected by an increase to the state pension age – living below the minimum standard of living was found to have doubled in the last decade.

The University’s Centre for Research in Social Policy (CRSP) conducted the research as part of its Minimum Income Standards programme, which calculates the minimum budget individuals require to cover their material needs and to participate in society.

Head Debbie Whiting launched it after seeing pupils so famished they were stealing from other children’s packed lunches.

“You can’t learn if you’re hungry,” she said. “Children need to be fed, clothed and warm.”

The food bank at North Denes juniors in Great Yarmouth, Norfolk, is thought to be the first at a British school.

Staff and some parents donate extra items from their shopping and a charity has given £1,500.

Mum Sadie Carter, who has two children at the school, said she fell to “rock bottom” after running out of money and was “crying for days”.

Nearly 10,000 of those will wake up on Christmas Day in bed and breakfasts, hotels or hostels where in many cases their family will have been put up in a single room, sharing bathrooms and kitchens with other residents.

Shirley Widdop, from Keighley, whose bill, based on a water meter, has risen by 35%, says: “It’s outrageous and like something from the 1930s.”
“We shouldn’t have to ration water.”

A report on poverty from the Joseph Rowntree Foundation shows that arrears for water bills are now the most common form of debt for the poorest families.

“I am on a water meter and because I’m on a low income I constantly worry about the bill being too high,” says the 51-year-old, who lives with two of her children.

In-work poverty is the highest it has been in 20 years and in a typical classroom of 30 children, nine are living in poverty, the Joseph Rowntree Foundation’s state of the nation report says.

Although successive governments have argued work is the fastest route out of poverty, the figures show 8 million people are living in poverty in households where at least one person is already in work.

The alarming figures come after the chancellor Philip Hammond revealed Brexit will make the UK worse off under any scenario.

The government estimates the UK economy could shrink by 3.9 per cent after 15 years under Theresa May’s Brexit plan, compared with staying in the EU.

But a no-deal Brexit could deliver a 9.3 per cent hit, the figures say.

Overall one in five of the UK population (22 per cent) are already in poverty – a total of 14.3 million people, and 56.5 per cent of those in poverty are living in household where someone is in work.

Campbell Robb, chief executive of the Joseph Rowntree Foundation, warned families could be “pushed over the brink”.

He said: “We are seeing a rising tide of child poverty as more parents are unable to make ends meet, despite working. This is unacceptable.

“It means more families are trapped in impossible situations: struggling to pay the bills, put food on the table and dealing with the terrible stresses and strains poverty places on family life.

“It’s time for us to decide what kind of country we want to be. As we leave the EU, we must tackle the burning injustice of poverty and make Britain a country that works for everyone.

“We can do this by taking action on housing, social security and work to loosen the constraints poverty places on people’s lives. No one wants to see more families being pushed over the brink.

“We have an opportunity to fix this and ensure everyone can reach a decent standard of living – it is one we must seize to make the country work for everyone after Brexit.”

In-work poverty has been rising even faster than employment, the report says, and has been exacerbated by many parents working in low paid service industry jobs with little chance of career progression “especially in hotels, bars, restaurants and shops”.

Any gains from the national living wage and tax cuts are often outweighed by changes to tax credits and benefits that top up low wages, while the cost of housing has risen.

Echoing the recent findings of the UN special rapporteur on extreme poverty, Philip Alston, the study concluded the scale of the cuts and their lopsided impact on the most disadvantaged were a policy choice, rather than inevitable.

“There were a lot of choices, and the government chose to balance the budget on the backs of the poorest,” said the study’s co-author, Jonathan Portes, a professor of economics at King’s College London.

The study examined the impact of spending on the NHS, social care, police, transport, housing and education between 2010 and 2015 on various groups in England, Scotland and Wales. It also looked at the expected impact of spending plans for these sectors to 2021-22, and tax and benefit changes.

On a per-head basis, reductions since 2010 were significantly higher in England – equivalent to about 18% – than in Wales (5.5%) and Scotland (1%), in part because the devolved governments chose to mitigate some effects of the cuts, it said.

The poorest 20% of people in England lost an average of 11% of their incomes as a result of austerity, compared with zero losses for the top fifth of households.