Dr John Chisholm warned that GPs were angry and disillusioned

The average GP conducts more than 10,000 consultations a year and spends just eight minutes with each patient.

The BMA wants to know whether GPs would be prepared to resign if new contracts have not been agreed in 12 months' time.

It says any new contracts should reduce the amount of bureaucracy and administration GPs are forced to do.

Family doctors also want less "open ended" commitments, a tighter definition of the role of the family doctor and for pay not to be closely linked to size of their patient list.

NHS Plan

Dr John Chisholm, chairman of the BMA's GP Committee, told BBC News Online that individual ideas for reform contained in the NHS Plan were laudable.

There has been a considerable welling up of anger and disillusionment

Dr John Chisholm, British Medical Association

He said the problem was that the government was trying to force through too much change in too short a time period.

He said: "Morale has been low in general practice for more than a decade now, but there has been a considerable welling up of anger and disillusionment in recent months.

"Workload is already unsustainable, and now we have the promise from government of lots more work coming from all different directions."

The NHS Plan sets a target for all patients to be seen by a health professional within 24 hours, and by a GP within 48 hours.

It also sets tough targets in areas such as standards, annual appraisals and minimum standards of care on major illnesses.

Dr Chisholm said it was simply not feasible for GPs to be expected to cope when the government was only planning a "very tiny" increase in family doctor numbers.

With good will on all sides it ought to be possible to make real progress

Department of Health

He also criticised the time limit targets as a "distortion of appropriate clinical priorities".

"Patients who need to see their GP most ought to be given priority, rather than simply saying that everybody has an absolute right to be seen."

Dr Chisholm warned that if the government did not take action then the prognosis for the NHS was bleak.

"Significant numbers of GPs would be likely to resign in those circumstances," he said.

The BMA will also issue advice to GPs on how they can reduce their workload.

One proposal is for GPs not to take on any new patients.

Dr Chisholm said: "Some GPs may well wish to close their lists because the workload they are facing in their surgeries is simply unsafe and unfair for their patients."

A spokesperson for the Department of Health said: "The GPC wants a new contract for GPs.

"As we have repeatedly told GP leaders the government also wants to see a new contract for GPs, and in fact the NHS Plan commits us to one.

"With good will on all sides it ought to be possible to make real progress."

Stephen Thornton, chief executive of the NHS Confederation, which represents health authorities and trusts, said: "We do not understand how the BMA has got itself to the point of calling for such a draconian measure as the mass resignation of GPs when both it and the Government want to negotiate a new contract. Why it is necessary to make such threats?

"There is no doubt that primary care is under significant pressure and there is a pressing need for more GPs.

"But the Government has already shown willing through a series of initiatives to improve conditions and recruitment."