Denis Campbell Health policy editor

Labour is demanding that MPs be allowed to debate and vote on “secret” plans for the NHS that they claim could lead to greater rationing of care and privatisation of health services.

The party says ministers are trying to push through the creation of “accountable care organisations” (ACOs) without proper parliamentary scrutiny.

Jonathan Ashworth, the shadow health secretary, has written to Andrea Leadsom, the leader of the House of Commons, urging her not to let “the biggest change to our NHS in a decade” go ahead without MPs’ involvement.

NHS England’s chief executive, Simon Stevens, and the government see ACOs as central to far-reaching modernisation plans that they hope will improve patient care, reduce pressure on hospitals and help the NHS stick to its budget.

ACOs involve NHS hospital, mental health, ambulance and community services trusts working much more closely with local councils, using new organisational structures, to improve the health of the population of a wide area. The first ACOs are due to become operational in April in eight areas of England and cover almost 7 million people.

Labour has seized on the fact that the Department of Health plans to amend 10 separate sets of parliamentary regulations that relate to the NHS in order to pave the way legally for the eight ACOs.

In his letter, Ashworth demands that Leadsom grant a debate on the plans before the amended regulations acquire legal force in February.

“Accountable care organisations are potentially the biggest change which will be made to our NHS for a decade. Yet the government have been reluctant to put details of the new arrangements into the public domain. It’s essential that the decision around whether to introduce ACOs into the NHS is taken in public, with a full debate and vote in parliament,” he writes.

A number of “big, unanswered questons” about ACOs remain, despite their imminent arrival in the NHS, he adds. They include how the new organisations will be accountable to the public, what the role of private sector health firms will be and how they will affect NHS staff.

Ashworth also says “the unacceptable secrecy in which these ACOs have been conceived and are being pushed forward is totally contrary to the NHS’s duty to be open, transparent and accountable in its decision-making. The manner in which the government are approaching ACOs, as with sustainability and transformation plans before them, fails that test.”

Stevens’s determination to introduce ACOs has aroused suspicion because they are based on how healthcare is organised in the United States. They came in there in the wake of Obamacare as an attempt to integrate providers of different sorts of healthcare in order to keep patients healthier and avoid them spending time in hospital unnecessarily.

A Commons early day motion (EDM) on ACOs also being tabled by Labour on Thursday, signed by its leader, Jeremy Corbyn, and other frontbenchers, notes that “concerns have been raised that ACOs will encourage and facilitate further private sector involvement in the NHS”.

In his letter Ashworth adds: “There is widespread suspicion that the government are forcing these new changes through in order to fit NHS services to the shrinking budgets imposed from Whitehall.” The EDM also notes “concerns that ACOs could be used as a vehicle for greater rationing”.

The King’s Fund, an influential health thinktank, denied that ACOs would open up NHS services to privatisation. “This is not about privatisation; it is about integration,” said Prof Chris Ham, its chief executive.

“There is a groundswell of support among local health and care leaders for the principle of looking beyond individual services and focusing instead on whatever will have the biggest impact in enabling people to live long, healthy and fulfilling lives,” added Ham.

Dr Chaand Nagpaul, the chair of the British Medical Association, backed Labour’s call for greater transparency but said care services should be integrated.

However, he added: “ACOs will not in themselves address the desperate underfunding of the NHS and may divert more money into processes of reorganisation. Current procurement and competition regulations create the potential for ACOs to be opened up to global private providers within a fixed-term contract and with significant implications for patient services and staff.”

The Department of Health refused to say if MPs would be able to debate ACOs. “It is right that local NHS leaders and clinicians have the autonomy to decide the best solutions to improve care for the patients they know best – but significant local changes must always be subject to public consultation and due legal process.