More areas in England will be placed under the country’s toughest coronavirus restrictions, Health Secretary Matt Hancock is expected to tell the Commons on Wednesday.

Pressure mounted on the Government to act as hospitals across England warned of increasing strains on services due to Covid-19 patient numbers, which have reached their highest levels during the pandemic, while 51,135 further cases and 414 deaths were reported on Tuesday.

Local authorities in Essex have declared a “major incident” as the number of coronavirus cases threatens to overwhelm health services in the county.

Meanwhile, ambulances were seen queueing outside hospitals including the Royal London Hospital in Whitechapel and Queen’s Hospital in Romford, both in east London, and Queen Elizabeth Hospital, Birmingham, om Tuesday, and a junior doctor in the capital said his his hospital was “aggressively overstretched” by Covid-19 patients.

Prime Minister Boris Johnson chaired a meeting of the Government’s Covid-19 Operations committee on Tuesday evening, when changes to the tier system were discussed.

With case rates rising in all regions of England, as well as the number of Covid-19 patients in hospitals, any review is likely to involve areas moving up a tier rather than down.

Areas that may be moved from Tier 3 to Tier 4 due to increasing case rates include parts of the East Midlands, such as Northamptonshire and Leicestershire, as well as all areas of the West Midlands metropolitan county.

Hartlepool in north-east England, along with a handful of areas in Lancashire – Blackburn with Darwen, Burnley, Pendle and Ribble Valley – could also be upgraded from Tier 3 to 4.

The Times also reported that ministers are also considering imposing the country’s toughest measures on parts of the south west and Cumbria.

Saffron Cordery, deputy chief executive of NHS Providers, warned “options were narrowing” and that moving areas into the highest tier was necessary.

“Pressures on the NHS in some parts of the country are rising at an unsustainable rate,” she said

“Thankfully, trusts in other areas have been helping out. But with the virus spreading fast alongside mounting winter pressures, the options are narrowing.

“We urgently need to get ahead of the outbreak. The Covid-19 tier review offers an opportunity to do that.

“It will require difficult decisions, moving millions more people to the highest level.

“The Government must act with boldness, speed and clarity in curbing the threat of Covid-19.”

Figures from NHS England showed there were 21,787 patients in NHS hospitals in England as of 8am on Tuesday, compared with 20,426 on Monday, and 18,974 at the first wave peak on April 12.

Five of the seven NHS regions in England are currently reporting a record number of Covid-19 hospital patients: Eastern England, London, the Midlands, south-east England and south-west England.

The other two regions, north-east and north-west England, remain below peak levels that were set in mid-November.

Meanwhile the number of further lab-confirmed cases recorded in a single day in the UK hit a new record on Tuesday, rising above 50,000 for the first time, to 53,135.

“The Government must act with boldness, speed and clarity in curbing the threat of Covid-19.

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.

The Government said a further 414 people had died within 28 days of testing positive for Covid-19 as of Tuesday, bringing the UK total to 71,567.

One senior doctor said some trusts in London and the South East are considering the option of setting up tents outside hospitals – something normally reserved for sudden events such as terror attacks or industrial disasters – to triage patients.

The number of Covid-19 patients in London hospitals is now higher than levels recorded at the peak of the first wave of the virus, with 5,371 as of 8am on Tuesday, according to NHS England.

During the first wave, the number of patients in London peaked at 5,201 on April 9.

Dr Susan Hopkins, senior medical adviser for Public Health England, said the “unprecedented levels” of Covid-19 infection across the UK was of “extreme concern”.

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.