The former head of NHS England has cast doubt on Conservative and Lib Dem plans to fund the health service, warning of a "financial hole" that requires "emergency action".
Sir David Nicholson said the so-called "Stevens plan" both parties have signed up to - which involves the government injecting £8 billion cash into the NHS while gaining £22 billion from efficiency savings - will be difficult to implement.
Labour is the only main party which has not signed up to the five-year plan drawn up by current NHS England chief executive Simon Stevens. It prefers a £2.5 billion Time to Care fund paid for by a mansion tax and tobacco levies.
Sir David stressed that the next government will have to suspend its ambitions about extra services and investment in order to deal with operational problems in the NHS caused by a funding gap.
He told BBC Radio 4's Today programme, "They [politicians] want to talk about extra services and extra investment when actually there is a problem there to face."
Sir David said the NHS would have to take "emergency action" such as vacancy freezes.
"What the public is being told at the moment is that 'we'll give you a bit of extra money and everything will be fine' and that actually these managers can deliver £22 billion and then everything will be fine," he said.
"So in a sense if they find it difficult to do that and I think most of them will, I think they are going to be blamed."