Dr Adrian Boyle, president of the Royal College of Emergency Medicine, said he thinks waiting times for December will be the worst he has ever seen.

More than a dozen NHS trusts and ambulance services declared critical incidents over the festive period as a severe flu outbreak and rising COVID cases are adding pressure to the system.

Read more: Number of flu cases in hospital seven times higher than November

Dr Boyle told Times Radio: "We went into this December with the worst-ever performance against our target and the highest-ever occupancy levels in hospital.

"We don't know about the waiting time figures because they don't come out for a couple of weeks; I'd be amazed if they're not the worst ever that we've seen over this December.

"What we're seeing now in terms of these long waits is being associated with increased mortality, and we think somewhere between 300-500 people are dying as a consequence of delays and problems with urgent and emergency care each week. We need to actually get a grip of this."

In November, 37,837 patients waited more than 12 hours in A&E for a decision to be admitted, NHS England figures show.

This is an almost 355% increase on the previous November, when about 10,646 patients waited longer than 12 hours.

Dr Boyle added: "If you look at the graphs, they all are going the wrong way, and I think there needs to be a real reset. We need to be in a situation where we cannot just shrug our shoulders and say 'This winter was terrible, let's do nothing until next winter'.

"We need to increase our capacity within our hospitals, we need to make sure that there are alternative ways so that people aren't all just funnelled into the ambulance service and emergency department.

"We cannot continue like this - it is unsafe and it is undignified."

Patients have been reportedly waiting hours for a bed and ambulances carrying patients have been stuck outside hospitals for hours as they wait to hand them over.

Sky News revealed on New Year's Eve that more than half of Staffordshire's ambulances were queuing outside Royal Stoke Hospital, with a paramedic and UNISON representative saying it was the "worst we've ever seen".

Last week, one in five ambulance patients in England waited more than an hour to be handed over to A&E teams.

Dr Boyle added it is "absolutely never too late" to get a flu vaccination and said those who are eligible should do so to reduce pressure on hospitals.