GPs have threatened to bring the NHS to a 'standstill' with unprecedented industrial action that includes slashing the number of appointments by a third.

The British Medical Association is urging family doctors back the disruption in a ballot that closes at midday today.

Patient groups last night described the move as 'selfish' and warned GPs risk harming those in need of care - and losing the public's support.

One NHS chief said the effect of a cap on the number of appointments could be 'catastrophic'.

It is feared as many as 3 million GP appointments a month could disappear if all family doctors kowtow to the BMA demands to slash numbers to just 25 a day. Some currently do 50, while the average is 37.

The action would start as early as this Thursday and last for 'months'.

The union say GP funding is being squeezed and the terms of a new NHS contract means 'many surgeries will struggle to stay financially viable'.

But GP partners, who own their practices and account for the majority of family doctors, earn an average of £153,400 a year - despite only one in three working full-time.

If GPs back the vote, they will be asked to take part in up to nine forms of protest, including one which would put a cap on the number of daily 'patient contacts'.

This includes face-to-face appointments, remote consultations and online messages.

The BMA says practices should limit these to 25 per GP per day, which is a third less than the current typical workload.

Dr Katie Bramall-Stainer, chair of the BMA's general practice committee, said family doctors will not be 'striking' but taking part in 'collective, premeditated, disruptive action' adding that the last time GPs took ‘collective action’ was in 1964 when family doctors collectively handed in undated resignations to the Wilson government.

A proportion of GPs staged industrial action in 2012 in protest against increases in pension contributions and a later retirement age for doctors. Estimates suggest that between a fifth and a third of practices took part in the action. 

She claimed the proposed action is aimed at hitting NHS England and the Department of Health and Social Care, rather than patients.

But Dennis Reed, director of Silver Voices, which campaigns for the over-60s, told the Mail: 'Our members, who are already struggling to obtain timely doctors' appointments, will be bemused and angered by this premature action by GPs.

'Having taken no disruptive action of this sort over the five years of the last Government, despite broken promises over recruiting more doctors, they are not giving negotiations a chance with the new Government.

'It is risible to say that the action is aimed at NHS England when it will be patients who suffer from further restrictions on appointments.

'The proposed action will just mean that more patients are forced to overload accident and emergency departments.

'Some older patients will be turned away from their GP practice and will go home, risking the symptoms worsening.'

He added: 'Silver Voices has supported the call for more resources for primary care and is sympathetic to GP workloads, but this selfish action over the detailed terms of generous contracts, risks losing the support of the public for their cause.

'The way to resolve these issues is mature negotiations, not sabre-rattling.'

Matthew Taylor, chief executive of the NHS Confederation, told the Guardian: 'If all GPs implemented the patient cap, that could have a catastrophic effect on the entire healthcare system.

'General practice is now supporting more patients than before the Covid pandemic, so any reduction in their activity will put more pressure on other services, including A&E.'

The ballot, which opened on June 17, could potentially mean GPs also stop performing work they are not formally contracted to do; refuse to cooperate with local data sharing arrangements; and ignore NHS 'rationing' restrictions on drugs.

Last Monday, NHS England told local health leaders to prepare for a 'reasonable worst-case scenario' in relation to the GP industrial action and warned it could affect the 'whole system', including A&Es.

And Professor Helen Stokes-Lampard, previously chair of the Royal College of GPs, told the NHS England board meeting on Thursday that the NHS is 'already starting to see tension' as a result of GP practices 'pulling back' from doing discretionary work.

GPs have not taken action since 1964 when family doctors collectively handed in undated resignations to the Wilson government.

But the BMA has led recent walkouts by junior doctors and consultants, hampering efforts to clear waiting lists that built-up during the Covid-19 pandemic.

The BMA has said the new GP contract, which will see services given a 1.9 per cent funding increase for 2024/25, means many surgeries will struggle to stay financially viable.

But official figures from NHS Digital show GP partners have seen their earnings - taken from practice profits - increase by 31 per cent in recent years.

Dr Bramall-Stainer revealed the action has been designed to be 'easy, sustainable and effective', adding: 'If it's done effectively, it's done collectively and it's done well, it will bring the NHS to a standstill very quickly - but not for patients, for all the NHS admin, the policymakers who have put in place these decisions that aren't helping patients.'

GPs launched a formal dispute over the issue in April after a referendum carried out by the union found 99 per cent of 19,000 GPs rejected the contract.

Dr Bramall-Stainer said: 'We don't want to put patients as piggy in the middle - we live in our communities with our patients, there are no barriers between us.

'We get a lot of the flak from the failings of the NHS and we agree with our patients and it's quite exhausting. The last thing we want to do is pitch patients against us.

'I don't think patients will really notice very much difference at all. And that's the plan.'

Dr Bramall-Stainer met with Health Secretary Wes Streeting on July 18 and union leaders hope such talks will continue.

Earlier this month she set out a number of asks of the Government, including a new Family Doctor Charter; a 'minimum investment standard' for general practice; an ask to build 'real-terms re-investment' into general practice; and a call for 'GP-to-patient list size ratios'.

Mr Streeting's first official visit in his new role was to a London GP surgery on July 8, where he pledged to 'bring back the family doctor' and 'fix the front door to the NHS'.

A Department of Health and Social Care spokesperson said: 'The Health and Social Care Secretary has met with the chair of the BMA's GP committee to discuss their priorities ahead of their ballot closing on July 29.

'However, it is important we plan for all contingencies, in every eventuality, to keep patients safe.'

NHS England said: 'We are continuing to work with GPs, the BMA and the government to avert any potential action but in the meantime the NHS has a duty to plan for any possible disruption and to ensure services continue to be provided for patients, so we will continue to work with local systems to help them plan in the event that collective action does go ahead.'

• This article originally stated that the proposed industrial action by family doctors was the first disruption by GPs in 60 years. It has been amended to clarify that while the chair of the BMA's general practice committee did claim it would be their first collective action since 1964, some GPs took part in strikes over pension contributions in 2012.