Sir Anthony Grabham, speaking in a personal capacity at the BMA conference in Harrogate, said one-third of the NHS was of high quality, the second reasonably good but the lowest third was of great concern.

He also said he doubted whether all the new money promised by the government to the NHS would ever materialise.

Sir Anthony argued that after half a century of underfunding, it was time to look at other possible ways of funding health care.

We are in terms of availability verging on third world medicine in what is one of the most affluent countries in the world

Sir Anthony Grabham

"I am not so sure that all of the promised increased funding will appear - or not in the promised timescale," he said.

"I am not imputing bad faith to the chancellor but inevitably, one remembers that politicians do sometimes change their minds.

"I remain somewhat sceptical about the value of these promises - we'll have to see and I still suspect that a different model of healthcare provision will have to be looked at some time in the future."

'Stressed' doctors

Sir Anthony, who became a consultant general surgeon in 1965 and has held many posts in the BMA, said: "There is much good in the NHS but there are also terrible problems."

It was unacceptable to have one million people facing long waits for operations, and for elderly people to be using their life savings to pay for private operations, he said.

Alongside the many good NHS hospitals, we know there are some that could do better

Department of Health

"Looking at this lowest third of NHS performance, we are in terms of availability verging on third world medicine in what is one of the most affluent countries in the world," he said.

Pressures on doctors were also becoming terrible.

"All over the country there are doctors who are anxious, stressed, overworked and demoralised because they can't look after their patients properly," he said.

He called on the government to stop manipulating the figures and start facing up to the problems in the service.

The government should "accept honestly and openly that some form of rationing and delay is inevitable in an under funded service," he said.

10-year plan

Responding to the speech, a Department of Health spokesman said: "If the BMA does not believe the extra billions of pounds we are spending on the NHS can deliver results, why have they recommended that their consultants accept a new pay deal based on that same investment programme?

"Alongside the many good NHS hospitals, we know there are some that could do better.

"We have a 10-year plan for investment and reform. We have more beds, more nurses and more doctors. There is some way to go, but a good start has been made."