Pressure is mounting on the Government over the “intolerable and unbearable” strain facing the NHS – with experts saying it is wrong to blame the pandemic for the current crisis.

Health leaders hit back at Downing Street suggestions the pandemic is a leading cause of the current situation, saying the problems are long standing and deep rooted.

On Tuesday, Downing Street said the Government has been “up front” with the public about the pressure the NHS faces this winter.

The Prime Minister’s official spokesman acknowledged the current pressure on the health service is an “unprecedented challenge”.

He added: “I think we have been up front with the public long in advance of this winter that, because of the pandemic and the pressures it’s placed (on) the backlog of cases, that this would be an extremely challenging winter, and that is what we are seeing.”

He told reporters the pandemic is among the biggest causes of the current pressures on the NHS, but also pointed to delayed discharges of medically fit people as a reason.

Asked if Prime Minister Rishi Sunak thinks the NHS is in crisis, his spokesman said: “This is certainly an unprecedented challenge for the NHS brought about, as I say, by a number of factors.”

Senior doctors say the NHS is on a knife edge, with many A&Es struggling to keep up with demand and trusts and ambulance services declaring critical incidents.

Labour has criticised the Government’s management of the health service, while the Liberal Democrats have called for Parliament to be recalled early.

In comments to the PA news agency on Tuesday, Dr Adrian Boyle, president of the Royal College of Emergency Medicine, said it is “disingenuous to blame the current situation on the pandemic”.

He added: “It is beyond doubt that Covid made a bad situation worse but the structural problems were there long before.

“Emergency care performance has been deteriorating for nearly a decade which is a consequence of wider staffing issues within the NHS, lack of beds and capacity and lack of social care – all problems which are due to under-resourcing.

“But this is fixable; we faced similar problems in the 1990s but only saw conditions improve once there was a political will to make them improve. We hope the current situation is acted upon in a similar manner.”

Dr Tim Cooksley, president of the Society for Acute Medicine, told PA: “Whilst the Government was ‘up front’ that the NHS was heading towards a winter of ‘unprecedented challenge’, the reality has been more intolerable and unbearable for staff and patients than envisaged.

“Whilst the twindemic of flu and Covid-19 are contributors, the fundamental problem remains a significant shortage of workforce leading to woefully inadequate inpatient bed and social care capacity. Current levels of staff burn out and poor morale markedly exacerbate this issue.

“The shocking NHS acute care situation needs emergency action. There needs to be a greater recognition and acceptance of the current situation by political leaders. This requires a four-nation approach.

“Clear and regular communication, an urgent workforce plan and engendering a belief in patients and staff that the situation can improve are essential in the short term.”

Matthew Taylor, chief executive of the NHS Confederation, said in a statement to PA: “Health leaders have been telling us that the pressures their staff are facing are becoming unbearable.

“The pressure is increasing every day, with more hospitals, ambulance trusts and other providers declaring critical incidents. There are no quick fixes to a crisis that has been long in the making, but the Government must do all it can to support the NHS at this time.

“High rates of flu and Covid, which have more than doubled, combined with ongoing issues with delayed hospital discharges, which is leaving over 12,000 medically fit patients stuck in hospital, are piling on the pressure.

“Ongoing industrial action is compounding the problem. We must always remember that the pandemic exacerbated many of the challenges facing the NHS but it did not cause them.

“We already went into the pandemic with far too many vacancies – they now stand at over 130,000 – and we were coming off the back of the longest financial squeeze in the NHS’s history.”

He added: “All of this meant the NHS wasn’t match fit for Covid and services continue to struggle against the widening gap between demand for care and the capacity we have in the NHS.

“It’s clear that the NHS is very fragile at the moment and it doesn’t take much to push it off kilter. With strikes set to take place this month, we continue our plea to the Prime Minister and trade unions to resume talks in order to avert planned and future strikes.

“Without a swift national resolution, patients will continue to suffer and that can’t be allowed to happen.

“We also need the Government to commit to do everything within its power to prevent the NHS from entering the next winter in this same fragile state that has sadly become the norm over recent winters.

“Tackling the growing health and care workforce crisis is essential.”

Ambulance staff are set to walk out on January 11 and 23 in a row over pay, while nursing staff will strike on January 18 and 19.

They should be elsewhere being looked after in social care; they can’t be discharged, which means that the patients in the emergency department can’t be admitted to hospital

Elsewhere, Sally Warren, director of policy at the King’s Fund think tank, said tens of thousands of people are waiting for social care assessments, which has an impact on hospitals.

She told BBC Radio 4’s Today programme “while they’re waiting, their condition might deteriorate and they may end up in the NHS system, be that with their GP, with NHS 111 or at the hospital front door”.

Richard Webber, spokesman for the College of Paramedics, said hospitals are “full of patients who should be elsewhere”, with many hospitals having 100 or 200 patients who should not be there due to being medically fit.

“They should be elsewhere being looked after in social care; they can’t be discharged, which means that the patients in the emergency department can’t be admitted to hospital,” he said.

It comes as NHS leaders in London said the London Ambulance Service will only wait 45 minutes to handover patients to A&E staff at the capital’s hospitals.