The editor of the Lancet medical journal has launched a public attack on the British Medical Association.
Ministers want GPs to extend surgery hours
Dr Richard Horton accused the BMA of being insulting and cynical towards the government, and failing to represent ordinary doctors.
He said it was not surprising ministers had attempted to bypass the BMA, and appeal directly to GPs over an extension to their working hours.
The BMA dismissed the claims, and said it wanted the best for patients.
Health Secretary Alan Johnson is writing to every GP in England urging them to accept the government's plans for extended surgery opening hours.
He hopes to persuade them to back a deal on evening and weekend opening.
The government has said it will impose a settlement if agreement cannot be reached with BMA, which has responded by claiming ministers' real agenda is to privatise services and undermine traditional general practice.
Writing in The Times newsaper this week, Dr Laurence Buckman, chairman of the BMA's GP Committee, said: "All the government cares about is voting marginals - they don't care about patients."
Dr Horton doubted whether the antagonism between the BMA and government was in the best interests of patients.
He said: "The government has invested truly unprecedented sums of money into the NHS, doctors' salaries have increased substantially, and the government now wants a very modest response to the money that they have invested.
"In the past two months the BMA has been sending out letters to doctors and patients creating a sense of paranoia and scare about the future of the NHS, suggesting that politicians are simply trying to dismantle the health service, take away doctors' surgeries, reduce the quality of care - and that is just a tissue of lies.
"We know that patients do want greater access to GP services, and we know that lack of access to GP services is costing the British economy £1bn a year.
"Why is it that the BMA is being so inflexible to what is a very reasonable government request?"
Dr Horton accused the BMA of failing to come up with a positive vision for the future of the NHS.
Dr Hamish Meldrum, chairman of the BMA Council, dismissed claims that the BMA was being inflexible, and said doctors wanted to see better access to patients.
However, he said the government had spent two years systematically trying to unpick the contract agreed with the profession in 2004.
He said: "That is what has angered doctors, it is not so much the question of extended hours, which doctors are happy to try to accommodate the government - and the public - on."
Dr Meldrum also rejected the idea that the BMA was not representative of ordinary doctors.
He said: "I would suggest that we are a lot more in touch with the feelings and views of doctors than Richard Horton."