Phil Johnson said ministers were refusing to accept reality

A spokesman said the protest was a "publicity stunt" organised by Doctor magazine, a trade journal for GPs.

"We are pleased to see so few patients will have been affected by this inappropriate action, which is designed to boost circulation of a magazine."

However, Phil Johnson, editor of Doctor, said that it was too early to tell exactly how many GPs had taken part.

He told BBC News Online: "Even if the final figures show that 50 practices closed their doors that would be completely unprecedented, and demonstrates just how strong the feeling is among GPs.

"This campaign was never just about GPs closing their surgeries. Thousands of doctors have supported the day, and this is just another example of ministers refusing to accept that there is a crisis in general practice."

Recruits needed

The protest was designed to highlight GPs' demands for thousands of new recruits, longer consultation time and shorter hours.

The average GP now has just eight minutes to see each patient and doctors claim they cannot deliver the necessary standards of care.

Dr Jonathan Reggler has closed his surgery for the day

While some surgeries closed, most GPs marked the day with posters and badges and by gathering petition signatures.

The day of action was dubbed inappropriate by the British Medical Association, which represents doctors, and also condemned by the head of the NHS Confederation.

But the BMA has recently gone on the offensive to win better conditions for overworked GPs and has balloted all 36,000 on the possibility of action.

One of the hotbeds of the protest is Weston-super-Mare, where every surgery except one closed to all but emergency cases.

Emergencies only

Dr Paul Seviour refused to close his surgery

Local GP Dr Michael Pimm told the BBC that he would only see emergency patients on Tuesday. Instead of seeing routine patients, he would concentrate on paperwork.

He said: "Over the last ten years the workload of a GP has risen inexorably, and it is now unsustainable. If it is not already, it is certainly soon going to harm patients.

"We need to blow the whistle on the system, and say it is not something that can go on in the long-term."

However, Dr Paul Seviour has decided to keep his surgery in Weston open.

He said: "I feel very strongly that one should not punish patients for disagreements one has with government."

I feel very strongly that one should not punish patients for disagreements one has with government

Dr Paul Seviour, GP, Weston-super-Mare

Dr Jonathan Reggler, a GP in Marlow, Buckinghamshire, has closed his surgery - the only one in the town - for the day.

He said: "We have shut the surgery because we want to draw attention to the fact that British general practice is under amazing strain.

"There are too few GPs, we don't have enough staff, and we don't have the ability to offer patients the level of service which they ought to expect."

Political reaction

Health Minister John Denham said the government was well aware of the pressures on GPs, and was working to address the problem.

"We want to increase the number of GPs, practice nurses and practice staff, we have agreed with the BMA a cut in millions of pieces of paperwork, and we are getting more money to frontline practices so they can invest in the development of their services.

Dr Michael Pimm: says workload has risen "inexorably"

"It is those measures that will make a difference to GPs who do feel under pressure today."

Shadow Health Secretary Dr Liam Fox said the medical profession had been frustrated by the way that the government had fuelled patient expectations - for instance by insisting that all patients saw a GP within 48 hours.

They were also angered by increased paperwork, waiting list initiatives, a reduction in referral rights and the growing recruitment crisis in primary care.

"It's no wonder that their morale is at an all-time low."

Nick Harvey MP, for the Liberal Democrats, said: "The government dreams up initiatives and gimmicks which raise the public's expectations. It is only natural that frontline staff such as GPs feel the squeeze.

"But hastily convened strike action will not help. It is only by increasing the numbers of doctors and nurses to international levels that we will get a top quality health service."