Labour and leading doctors are piling pressure onto Health Secretary Jeremy Hunt, as the health service faces another series of crises and funding gaps.
In Parliament, Labour will stage an all-day debate, demanding that the government come up with a solution to the latest NHS crisis.
The Royal College of Physicians (RCP), which represents some 33,000 doctors in the country, has written a damning letter to the prime minister, warning that lives are being put at risk.
The twin attack comes after a National Audit Office report prompted the British Medical Association to claim the government's plans to extend access to GPs in England are in "complete disarray".
Labour will call for additional funding for social care, an improved NHS settlement for the NHS and social care in the spring Budget, and a commitment to a four-hour waiting time.
The letter from the RCP said: "Our NHS is underfunded, under doctored and overstretched. Patients are waiting longer on lists, on trolleys, in emergency departments and in their homes for the care they need.
"An increasing number of people, although clinically ready to go home, cannot safely leave hospital as the care system is unable to cope.
"People's lives are being put at risk or on hold, affecting families across the country."
The Department of Health has promised additional funding and 5,000 more doctors in general practice by 2020 in order to meet an election promise for weekend and evening access to GPs.
But the National Audit Office report found that there were shortfalls in training places, early retirement, and increased part-time working, which means there may be 1,900 fewer GPs by 2020 than health authorities expect.
It added that the department had failed to evaluate the consequences of the proposals or show that they can provide value for money from existing services.
Funding the extended hours commitment will cost £230 per hour for every 1,000 patients, compared to £154 during normal opening hours, the watchdog said.
The chairman of the British Medical Association's GP committee, Chaand Nagpaul, said the report was "further evidence that the Government's plans for extending patient access are in complete disarray".
Dr Nagpaul said: "Policy-makers have underestimated the number of GPs required to deliver their promises by almost 2,000.
"This comes at a time when the NHS is already suffering from a chronic shortage of GPs with one in three practices having unfilled doctor vacancies."
An NHS England spokesman said: "The NAO seem to be criticising the rather obvious fact that it inevitably costs more to provide evening and weekend urgent primary care services than it does during Monday to Friday, nine to five.
"The alternative would be that patients simply head to A&E, with all the consequences that brings for more major cases.
"No-one is suggesting each individual GP practice should offer this extended access, but there's quite wide agreement that - as GP numbers expand - practices do need to club together to offer this service, a bit like the out-of-hours duty chemist rota.
"Across much of London, Manchester and a fifth of the country, GPs are already doing this, and more areas will follow next year.
"The NAO are wrong to criticise the value for money of general practice, given that the per-patient cost of a year of GP care is less than the cost of just two A&E visits.