Downing Street has said the government is “providing the NHS with the funding it needs”, amid warnings of a winter crisis at hospitals.
The Royal College of Emergency Medicine has said deaths of up to 500 people each week could be caused by delays in emergency care.
And the British Medical Association (BMA) has said future of the health service was “balanced on a knife-edge”.
It comes as ambulance staff are set to walk out on January 11 and 23 in a dispute over pay.
Nursing staff will strike for two consecutive days on January 18 and 19.
Asked about the situation in hospitals, the prime minister’s spokesperson said on Tuesday: “I think we are confident we are providing the NHS with the funding it needs – and as we did throughout the pandemic – to deal with these issues.”
The spokesperson said the pandemic was among the biggest causes of the current pressures on the NHS, but also pointed to delayed discharges as a reason.
They added it was an issue the government had “recognised and have been seeking to address this year with additional funding into the system”.
Asked if the PM thought the NHS was in crisis, the spokesperson said: “This is certainly an unprecedented challenge for the NHS brought about, as I say, by a number of factors.”
Matthew Taylor, chief executive of the NHS Confederation said the current situation was “very difficult” with many trusts declaring critical incidents.
He told the BBC said that over the longer term, the NHS needs “sustained investment”.
Mark Harper, the transport secretary, earlier rejected the suggestion the health service did not have enough money. “I don’t agree with that,” he told Sky News. “There’s record investment.”