Health Secretary Andrew Lansley had a very different vision for NHS reforms but the version that is going through is being supported by the Prime Minister, despite widespread opposition / Getty Images

Even the Health Secretary is unhappy with how the Health and Social Care Bill now stands. But the PM seems determined to plough on in a way that, critics say, typifies his style in office

There are few things upon which everyone agrees about Andrew Lansley's hated Health and Social Care Bill. But they do agree on this: no one wants it.

Not even Andrew Lansley. Not really. His original vision of the Health Secretary being released from day-to-day responsibility for the NHS, GPs in control as competition let rip – that's all gone. In its place rests a piece of legislation amended some 2,000 times, expanded to more than 450 pages, so complex and multifarious that even Heath Robinson might struggle to unpick its component parts. "This is not even what Lansley set out to do," admits a ministerial friend, wearily.

The Bill will take another kicking in the House of Lords tomorrow when government insiders expect to suffer up to a dozen defeats, though none of them fatal.

And yet still David Cameron insists it must go on. Despite three members of his own Cabinet briefing against it – and Mr Lansley – the Prime Minister will this week make another attempt at selling a cure to a public unconvinced that the patient is really ill. Expect a sleeves-rolled-up visit to a hospital. But don't expect him to wash his hands of a project which, rightly or wrongly, could cost him the next election.

Almost two years in the making, the once eye-catching plan to take the axe to the NHS's bloated bureaucracy and hand power to family doctors has become a metaphor for Mr Cameron's worst failings as Prime Minister – lack of attention to detail, a hands-off management style, misplaced loyalty to old friends and a deep-rooted belief that shouting at the Despatch Box will silence one's critics.

One exasperated government strategist resorted to quoting Malcolm Tucker, the foul-mouthed spin doctor from The Thick of It, to sum up how bad things have become: "It is a fucking omnishambles." At one stage during one of the many moments of paranoid crises that have gripped the reforms, civil servants were ordered not to commit anything to paper to prevent embarrassing leaks.

It has been another terrible week for the Health Secretary. Friends described Rachel Sylvester's column in The Times (saying he should be "taken out and shot") as a "depth-charge bomb". The ConservativeHome report on three cabinet ministers voicing doubts about the Bill was likened to "lobbing in a hand grenade".

Downing Street stresses that no senior minister has raised concern with the Prime Minister, who remains "totally committed" to the reforms which he believes have broader support "in the country" than media reports suggest. "The status quo is not an option," said a close aide.

Mr Cameron remains fiercely loyal to Mr Lansley, who was his boss in the 1990s when the future prime minister worked in the Conservative research department. As with Andy Coulson, his disgraced former spin doctor, there is a sense that the Prime Minister is willing to stand by a friend long after their continued presence has caused him damage politically.

In a meeting on Monday, Mr Cameron banged the table and told Mr Lansley: "We've not shed blood on these proposals not to go through with them... Let's really get out there and work to sell them." The problem is that every attempt to explain the reforms soon drifts into either generalisations ("efficiencies, choice, competition"), platitudes ("giving power to doctors and nurses") or jargon ("clinician-led commissioning").

There has also been the lack of consistency; where once ministers boasted of having the professional bodies signed up and on board, they now claim angry and almost universal opposition is an inevitable outcome of radical reform. What was once hailed as the biggest change in the NHS for 60 years is now being represented as a logical, small-scale continuation of Blairite reforms. In July 2010, Mr Lansley boldly declared that "people voted for change" – which doesn't sit well with his pre-election promise of no more top-down reorganisations.

The Government's favoured option now is that the Bill is further amended in the Lords and limps on to the statute book just as the next Queen's Speech is unveiled in May. One senior government source described the constitutional progress of the Bill: "Everyone expects the Bill will go through the House of Lords, and then the House of Commons. It will receive Royal Assent from the Queen. And then there will be a reshuffle and Lansley will be told to fuck off."

In a sign of the fiasco at the heart of the Government, it is now the Liberal Democrats who speak most warmly about the legislation, having rewritten large passages in a coup led by Baroness Williams. The Lib Dems are furious after working hard behind the scenes to be constructive. "The Tories are flip-flopping all over the place," says one. "Cameron is panicking about local elections in May," says another, adding pointedly: "It is very much their Bill."

Andy Burnham, the shadow Health Secretary, is preparing to table amendments to the Bill which would delay the increased marketisation of the NHS – the most controversial section – until 2016. "People haven't voted for this sort of NHS," he told The Independent on Sunday. "David Cameron does not have a mandate and it is essential that a general election intervenes before these game-changing elements are put into practice. We are going to give Cameron the fight of his life because he is wrong."

He vowed to repeal the Bill if Labour wins the next election. But he insists the Bill could yet be killed off. "If I read the newspapers I am led to believe half the Cabinet has joined Labour's Drop the Bill campaign."

Labour is pinning its hopes on the release of the national risk register, detailing the dangers of the reforms. The Government is resisting publication, and Labour has called a vote on the issue. At least 10 Lib Dems back its release. If the report was made public and it did contain stark warnings about the impact of the shake-up, it could prove lethal to the Government's programme.

As the farrago has dragged on, costs have risen too. Redundancy payments to lay off the bureaucrats are expected to top £800m, with doubts about the claimed future annual savings of £1.5bn. In January last year, the official impact assessment suggested £7.7bn net savings, but after the pause and major rewriting of the Bill, the benefits were downgraded to £6bn. Hundreds of thousands of pounds have been spent on getting the Bill passed.

Money is not in abundance in the NHS, which must save £20bn through efficiencies by 2015. The extra cash is due to be ploughed back into the service, because spending increases will be marginal and nothing like the 3 or 4 per cent seen under Labour. The big problem for the Government is that if the reforms do not work, or falter in any way, throwing money at the problem will not be an option.

Which means Mr Cameron could be left with a real mess on his hands come the next election, and he can't argue he wasn't warned.

Reforming the reforms: How the changes to the NHS were revised

Lansley's original plan

Layers of bureaucracy, including primary care trusts (PCTs) and strategic health authorities, would be swept away and by 2013 GPs handed sole control of £60bn to buy services through commissioning consortia. The regulator, Monitor, would be charged with promoting competition: hospitals and trusts would be pitted against each other in a system modelled on the private utilities market. The Secretary of State for Health would have no day-to-day responsibility for the NHS.

What changed?

After the "pause", the timescale slipped and the deadline for GPs to take over was no longer mandatory. Nurses and hospital doctors are also involved in the design of services, with commissioning consortia becoming clinical commissioning groups (CCG). It means 151 PCTs have been replaced by 279 (CCGs), many hiring the same staff. The National Commissioning Board will take responsibility for a £21bn budget, raising fears about a return to top-down control. Competition is no longer based on price but service quality. The Secretary of State will remain responsible for the NHS. Still a sticking point is the plan to raise to 49 per cent the cap on private work that hospitals can do. This has fuelled claims of "privatisations by the back door".

Lining up against the Bill

British Medical Association

Chartered Society of Physiotherapists

Community Practitioners' and Health Visitors' Association

Faculty of Public Health

GMB union

Institute of Healthcare Management

NHS Consultants' Association

Patients Association

Royal College of GPs

Royal College of Midwives

Royal College of Nursing

Royal College of Paediatrics and Child Health

Royal College of Psychiatrists

Royal College of Radiologists

Unison and Unite unions