The head of the British Medical Association (BMA) has written to Prime Minister Theresa May, accusing her of "playing down" the crisis in NHS hospitals.

The BMA's chairman, Dr Mark Porter, said the underfunding of the NHS and "salami slicing" has led to a situation where patients' lives and wellbeing are being put at risk.

On Saturday, Downing Street warned GPs in England who refuse to open surgeries from 8am to 8pm, seven days a week will lose funding unless they can prove there is no demand from patients.

It sees GPs as part of the solution to easing the pressure on A&E departments by offering more appointments to patients.

But the BMA has accused Number 10 of scapegoating doctors and said one in three GP practices have unfilled vacancies and eight in 10 GPs feel so overstretched they are unable to provide safe care.

Professor Helen Stokes-Lampard, the chairwoman of the Royal College of GPs, also said the Prime Minister's intervention was "extremely unfortunate" and the plans were "misguided".

Figures out on Friday showed m ore than four in 10 hospitals in England declared a major alert in the first week of the year

Some 65 out of 152 trusts raised the alarm as bed shortages intensified and A&E departments became overwhelmed.

Overall, NHS hospitals issued 222 serious alerts in six days, saying they were experiencing major pressures - around six times higher than the previous six days.

In his letter, Dr Porter called for a meeting with Mrs May, adding: "I have been horrified to see the position which you have taken in responding to the current crisis in the NHS in England.

"In playing down what is happening in hospitals up and down the country - with beds at full capacity, daily breaches in A&E, and critical operations being cancelled - and in then seeking to lay the blame on general practice, your government appears to be seeking deliberately to distract from what is really happening in the NHS.

"The Government's attempt to scapegoat GPs for a system-wide crisis resulting from years of underfunding must be addressed.

"The current crisis in the health service extends well beyond A&Es, with all parts of the NHS, including GP surgeries, working as hard as possible to keep up with demand."

Dr Porter added: "The issues which we are seeing: hospitals declaring alerts indicating their organisations are unable to deliver comprehensive care; trolleys with seriously ill patients backed up in corridors; patients being sent home because there are no beds available for them or waiting hours on end in ambulances before being admitted, are not due to a difficulty in accessing a GP and certainly will not be solved by penalising and scapegoating an already critically under-resourced and understaffed general practice."

Dr Porter said the Government's position it has "fully funded" the NHS's own plan for modernising services "is now widely discredited - not least by the chief executive of NHS England" Simon Stevens.

He added: "The continual salami slicing, the presentation of cuts as improvements in the face of palpably deteriorating services and the scapegoating of those who work in the service have led to this situation, one in which patients' lives and well-being are at risk. This should not be acceptable for any government."

The letter comes as the Health Service Journal (HSJ) reported that local areas have predicted the demand for emergency care must fall over the next three years if they are to meet their financial goals.

The HSJ analysed data from 11 Sustainability and Transformation Plans (STPs) across England.

Some 44 STPs have been drawn up across the country to set out plans for transforming services while saving cash.

Emergency admissions to hospital have been rising year on year.

Dr Mark Holland, from the Society for Acute Medicine, said: "I think that Dr Porter gives a very articulate description of the problems we face.

"We all accept that there is are no easy solution.

"The Government must except there is a problem and work with us to find solutions.

"Marginalised and attacking general practitioners is wrong.

"The real issue is that every part of the NHS is struggling.

"The patients we are seeing this winter are sick.

"If emergency departments are full of sick people, the problem is not due to inadequate primary care.

"The problem is that we do not have enough beds to accommodate patients.

"The patients who are wrongly perceived as needing a GP and do not need to come to the A&E are not causing this problem.

"The problem is the number of sick patients who we cannot get home once they are better."