A paramedic of 30 years had described one of the worst shifts of his career after he was forced to tell patients they could wait 10 hours for an ambulance.
Richard Webber says a controller called for help on at least two occasions as no ambulances were available for people suffering cardiac arrests.
At that point, virtually all of the ambulances in his area were queued outside his local hospital waiting to offload patients, the College of Paramedics spokesman told BBC Radio 4's Today.
It comes after more than a dozen NHS trusts and ambulance services declared critical incidents over the festive period, with officials saying rising flu cases and the impact of the COVID-19 pandemic have hit the health service hard.
Webber told how he had to ask several patients if they had relatives who could drive them to hospital instead of waiting several hours for an ambulance.
Watch: Paramedic describes 'worst shift of his career' as NHS struggles with record ambulance wait times
Describing another challenging shift last week, he says he took a patient in his nineties who was bleeding internally to hospital.
He was taken off the ambulance, assessed in hospital, then put back in the vehicle and ended up waiting five and a half hours for a bed.
Webber said there were eight other ambulance crews waiting to offload their patients, six of whom were in their eighties, and the youngest of whom was 77.
“These are patients who absolutely need to be in hospital, they’re older patients, they’ve got serious conditions, they need to be treated, there is no space… Meanwhile when you’re with your patient you can’t go to the next one.”
Webber said there have been a number of cases across the country where patients have "come to significant harm" because they've had to wait too long for an ambulance.
He said people who’ve had falls and have spent 10 to 12 hours lying on the floor and have suffered from rhabdomyolysis - a condition that can lead to heart or kidney damage.
While the end of December and early January is always a challenging time for the NHS, high levels of COVID, Strep A and flu have added to the pressure. Webber, added: “It’s certainly the worst I’ve ever seen it.”
NHS England data shows flu-related admissions rose 79% in a week, with an average of 3,746 flu patients in hospital in the week to 25 December.
This was up from 2,088 the previous week, and significantly higher than the 772 at the start of the month, and numbers are comparatively far higher than 2021.
More than nine in 10 beds filled (over 93%) were filled compared to 86% for the same period last year, NHS data shows, with the number of free beds at its lowest since records began in 2012.
Webber said part of the problem is a lack of investment in the social care system, with patients who have been deemed fit being kept in beds because there is nowhere else for them to go.
"Many hospitals have 100 or 200 patients who shouldn’t be in the hospital," he added.
Hospital capacity “continues to be impacted by delayed discharges”, with 12,313 beds a day taken up by patients who were ready to leave, NHS England said.
Ambulance handover times are currently at a record high, with one in five patients in England waiting more than an hour to be handed to A&E teams in the week leading up to Christmas.
NHS trusts have a target of 95% of all ambulance handovers to be completed within 30 minutes, with 100% within 60 minutes, but many are nowhere close to this.
The Royal College of Emergency Medicine (RCEM) has said this winter is set to be the worst ever for A&E waiting times.
Its president Dr Adrian Boyle said he "would not be at all surprised" if December turned out to be the worst month on record for hospital occupancy.
The RCEM warned on Sunday that between 300 and 500 patients would die each week in emergency care due to long waiting times.
On top of this, ambulance staff are set to strike on 11 and 23 January in a dispute over pay, while nursing staff will walk out for 48 hours from 18 January.
Labour and the Liberal Democrats criticised the government for inaction over recent days, with the latter calling for Parliament to be recalled to discuss the situation.
Shadow health secretary Wes Streeting laid the blame at the feet of the Conservative government, who he accused of “mismanagement” of the NHS.
The Labour MP branded it “inexplicable” that neither Rishi Sunak nor any of his ministers had offered answers to the challenges facing the UK’s hospitals.
Lib Dem health spokesperson, Daisy Cooper, said: “This is a life or death situation for huge numbers of patients. The NHS is collapsing in front of our eyes whilst the prime minister and health secretary are nowhere to be seen.
“This is a national crisis and the country will never forgive the government if they refuse to recall parliament whilst hundreds of people die in parked ambulances or hospital corridors.”
Number 10 says the pandemic was among the biggest pressures on the NHS, but critics say more than a decade of underfunding has led to this point.
A spokesperson for the NHS 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.”