David Cameron faces a revolt by his own MPs over his flagship policy to raise National Health Service spending by a level above inflation each year.
Two-thirds of Tory backbenchers oppose his plan to exempt healthcare from any spending cuts that an incoming Conservative Government would make to tackle the "black hole" in the public finances. Mr Cameron could come under pressure to rethink his strategy if he becomes prime minister, a poll by ComRes suggests.
Asked whether the NHS should receive guaranteed spending increases in real terms during the course of the next Parliament, 29 per cent of Tory MPs agreed and 62 per cent disagreed. Only 33 per cent believed the current NHS model, funded from general taxation and free at the point of delivery, was sustainable for the next 60 years, while 62 per cent did not.
The poll will fuel the debate within the Conservative ranks about Mr Cameron's decision to spare health from the squeeze that other major Whitehall departments would face.
Tory MPs want him to make a stronger commitment to reforming the NHS, but he also faces pressure to reassure voters that the system would be safe in his hands, after Daniel Hannan, the outspoken Tory MEP for South-East England, described the NHS as a "60-year mistake".
One Tory MP said last night: "The hope is that we would be more radical on health in office than we say now, that he [Mr Cameron] is anxious not to frighten the horses. But there are concerns about cutting other areas and allowing the health budget to carry on rising regardless. It cannot be exempt from financial pressure or reform."
Writing in The Independent today, Tim Montgomerie, the editor of the ConservativeHome website, warns that the Tory pledge to outspend Labour on the NHS will require more painful cuts in other budgets such as defence, transport and welfare. He urges Mr Cameron to spell out where the axe would fall, saying: "Without a clear mandate there is going to be little defence against the wave of hostility that will greet the toughest of public spending settlements."
Warning that Mr Cameron's support is "wide but not necessarily deep", Mr Montgomerie adds: "A clear and positive vision for getting Britain out of Labour's mess will give him the strength of support that he will need for the very tough years that lie ahead."
Labour will try to exploit the Tory turmoil by running an autumn campaign exposing the "two faces" it claims the Conservatives present to the public on health and other issues. Labour sources claim the party's private polls show that voters are wary of Mr Cameron's promises to protect the NHS at a time when he plans to cut other budgets – a fear echoed privately by some Tory MPs.
There could be more trouble for the Tories on the issue at their party conference in October. The right-wing Freedom Association, which has backed Mr Hannan's controversial remarks, is staging an event that will include the Progressive Vision group, which has set up a "NoNHS" campaign. The association has accused the Tories of trying to stifle debate on health.
Cameron allies insist it is his views, not Mr Hannan's, which will determine Tory policy and say he is confident of winning public support for his stance. They won a boost yesterday when a separate ComRes poll for The Independent On Sunday found that 47 per cent of people disgreed with the proposition that the NHS would be safer under Labour than the Tories, while 39 per cent agreed.
The survey, conducted for BMI Hospitals, suggests that older MPs in all parties are much more attached to the NHS than the younger generation in Parliament. Some 72 per cent of MPs born before 1950 believe the current NHS model is sustainable but only 42 per cent of those born after 1960 agree. There is a similar generational split over the use of the private sector to treat NHS patients.
Tory MPs support the introduction of tax breaks for private healthcare fees, by a margin of 55 to 31 per cent. But the Chancellor, Alistair Darling, said: "Tax breaks for private healthcare would take money away from the health service and undo the real progress we have made with the NHS over the last 12 years. After a torrid two weeks, David Cameron can no longer hide the two faces of his party on the NHS – this poll shows where the heart of the Tory party lies."
Andrew Hawkins, of ComRes, said: "These results show that Conservatives and younger MPs are more sympathetic to the role private sector companies can play in the NHS than their older, non-Tory counterparts.
"Given that we can expect a relatively high turnover of MPs at the next general election, perhaps more than a third of the House, we should expect that the direction of travel for the House is towards more support for private sector involvement in the health service."