Tough new coronavirus restrictions are needed to avoid 'catastrophe', a top scientists has said.
On the day that the UK recorded more new Covid-19 cases than at any other point in the pandemic, experts have piled pressure on the Government to act.
Their interventions comes ahead of a schedule change to tier areas by Health Secretary Matt Hancock in the House of Commons tomorrow.
Prof Hayward, professor of infectious diseases epidemiology at University College London, said widespread Tier 4 restrictions - or even higher - are likely to be needed as the country moves towards "near-lockdown".
He told BBC Radio 4's Today programme: "I think we are entering a very dangerous new phase of the pandemic and we're going to need decisive, early, national action to prevent a catastrophe in January and February."
Asked whether a national Tier 4 lockdown should be brought in, NHS Providers deputy chief executive Saffron Cordery told BBC Radio Five Live: "I think we need to see, yes, as much of the country as possible in Tier 4."
She said some trusts are reporting up to three times the number of Covid-19 patients as at the peak of the first wave.
NHS England chief executive Sir Simon Stevens has warned that doctors and nurses are "back in the eye of the storm".
Figures from NHS England show there were 20,426 patients in NHS hospitals in England at 8am on Monday, compared with 18,974 on April 12.
Sir Simon said: "Many of us have lost family, friends, colleagues and - at a time of year when we would normally be celebrating - a lot of people are understandably feeling anxious, frustrated and tired.
"And now, again, we are back in the eye of the storm with a second wave of coronavirus sweeping Europe and, indeed, this country."
Trusts in England were told in a letter just before Christmas to begin planning for the use of Nightingale hospitals, although concerns have been raised around staffing the sites.
One senior doctor said some trusts in London and the South East are considering the option of setting up tents outside hospitals to triage patients.
Emergency medicine consultant Simon Walsh said staff are working in "major incident mode" and called on the Government to set out a "coherent plan" to get through the coming weeks.
Paramedics in London are receiving support from other ambulance services in the South as they receive up to 8,000 emergency 999 calls each day.
South Central Ambulance Service (SCAS) said it is "pre-warning" the military and fire service that paramedics may need help after an average increase of 10% in 999 calls over the Christmas period and a threefold rise in 111 calls, along with a 60%-70% increase in absence rates with staff symptomatic or self-isolating.
The Government said a further 357 people had died within 28 days of testing positive for Covid-19 as of Monday, taking the UK total to 71,109.
The number of further lab-confirmed cases recorded in a single day in the UK also hit a new high of 41,385 at 9am on Monday, rising above 40,000 for the first time, according to Government figures.
The true number is likely to be higher because figures do not include information from Scotland and Northern Ireland, which did not report data between December 24 and 28.
It is not possible to make direct comparisons with the level of infection during the first wave of the virus, because mass testing was only introduced in the UK in May, but it has been estimated there may have been as many 100,000 cases a day at the peak in late March and early April.
More than six million people in east and south-east England went into the highest level of restrictions on Saturday, meaning 24 million - 43% of the population - are now affected.
Lockdown measures are also in place across the other three home nations, after mainland Scotland entered Level 4 restrictions from Saturday for three weeks, and a similar stay-at-home order is in place in Wales.
Northern Ireland has also entered a new six-week lockdown, and the first-week measures are the toughest yet, with a form of curfew in operation from 8pm, shops closed from that time and all indoor and outdoor gatherings prohibited until 6am.
