An NHS chief denied that the health service is in the grip of a winter 'crisis' today - despite tens of thousands of operations being delayed.
Professor Keith Willett, NHS England's director for acute care, admitted the drastic step of postponing all routine procedures and turning away non-urgent patients from A&E was 'not ideal'
The former surgeon suggested the situation was at its worst since the 1990s, and braced people for the possibility that further delays could be needed.
But Prof Willett insisted the health service was 'better prepared' for the seasonal pressures than ever before, saying: 'A crisis is when you haven't got in place mitigations and you haven't got a plan to deal with it.'
The comments came as Theresa May faced demands to 'get a better grip' on the NHS, with senior Tory MP and former GP Sarah Wollaston warning that ministers had to 'understand the sheer scale of the increase in demand across health and social care'.
In a drastic step to try to free up hospital staff and beds, NHS England urged hospitals to defer day-case procedures and routine outpatient appointments until January 31
Health Secretary Jeremy Hunt was accused of 'running scared' of defending his performance after he did not take to the airwaves this morning - although aides said he would be doing interviews later.
In an unprecedented move, NHS chiefs have demanded radical action to free up beds and medical staff. Casualty units are under 'extreme and sustained' pressure with flu cases on the rise.
Up to 55,000 non-urgent operations will be postponed until February, along with thousands of outpatient appointments and scans.
Managers will be allowed to put patients on mixed-sex wards and consultants will be assigned to casualty units to assess patients on arrival. Anyone not judged to be seriously ill faces being turned away.
An A&E consultant at University Hospitals of North Midlands NHS Trust apologised for the 'third world conditions' endured at his hospital this weekend.
Dr Richard Fawcett revealed that the department had run out of corridors to house patients. He blamed the crisis, which saw some patients have to wait for 12 hours, on overcrowding.
Government figures also reveal confirmed cases of flu have risen 50 per cent in a week and experts are worried about an especially aggressive 'Australian' strain.
It was responsible for the worst flu outbreak in 50 years Down Under and has already claimed a number of lives in Ireland.
There were reports yesterday of waits of up to ten hours at casualty departments and managers issued social media alerts pleading with the public to stay away.
Two NHS bosses said the pressures were the worst in 30 years with one doctor apologising for 'Third World' conditions.
However, Prof Willett told BBC Radio 4's Today programme: 'I fully accept that for the individual that will be really very uncomfortable.
'But what we know is if we don't have a plan in place and we don't do this in a structured way, what will happen, as we've had in previous winters, is lots of last-minute cancellations which is really distracting for patients, it's inconvenient, it upsets the plans they've put together with their family, particularly for elderly patients where their care needs are often quite significant.'
Prof Willett went on: 'We've gone into this winter in a way that we've never prepared before, so we went into the winter before Christmas having cancelled fewer elective operations than we had previously, discharges from hospital were at a lower level than they had been previously, so we were better prepared.
'We've also set up a national, regional and local structure - if you like, a winter pressures protocol - which we are invoking now and we are monitoring a whole series of things, activity in the service and the pressures.
'We are monitoring the weather alerts in anticipation of weather changes because we know that's important, and we also monitor the seasonal illnesses like flu.
'We've started to see those change, that's why the National Emergency Pressures Panel has now come out with these clear recommendations.'
Dr Wollaston, chair of the cross-party Health Select Committee, said the NHS was running a 'full stretch' and there was still 'not enough money' being spent - even though budgets have risen significantly in real terms since 2010.
'The point is, if you have a very major increase in people who are living longer with complex conditions, that produces particular demands on the health system that I think they need to get a better grip on, to understand the sheer scale of the increase in demand across health and social care. And that's what they need to do better planning for,' she said.
The first week of January is always busy with patients coming in with flu, chest infections, heart attacks and strokes.
But doctors say the pressures this year are greater even than in January 2017 which was itself considered unprecedented.
It is the first time NHS England has told hospitals to take such drastic measures during the winter.
Health Secretary Jeremy Hunt was accused of 'running scared' of defending his performance after he did not take to the airwaves this morning - although aides said he would be doing interviews later
A number of ambulance services are also under severe pressure, with two even resorting to taxis to ferry patients to hospital
The measures were announced by Bruce Keogh, the NHS medical director, following a meeting of the National Emergency Pressures Panel, which includes representatives of the Royal College of Surgeons and the Royal College of Nursing.
Afterward Sir Bruce said: 'I want to thank NHS staff who have worked incredibly hard under sustained pressure to take care of patients over the Christmas.
'We expect these pressures to continue and there are early signs of increased flu prevalence.
'The NHS needs to take further action to increase capacity and minimise disruptive last-minute cancellations. That is why we are making these further recommendations today.'
The main measure is the postponement of tens of thousands of pre-planned operations due in January.
NHS England, which runs the Health Service, said up to 55,000 non-urgent operations would probably be delayed, including hip and knee surgery and cataract procedures.
This figure could rise to 350,000 if day case procedures are included, although officials said this was unlikely.
Cancer surgery or any other procedure which is considered urgent will not be delayed. Patients will receive letters in the post if they are affected.