Lockdown measures will remain in place until at least March 8, Boris Johnson said as he earmarked that date to begin the reopening of England’s schools.

The Prime Minister confirmed that hopes of pupils returning to class after the February half-term have been abandoned as the battle with coronavirus remained “perilous”.

Government figures showed a further 1,725 people had died within 28 days of testing positive for Covid-19 as of Wednesday, bringing the UK total to 101,887, while there were a further 25,308 lab-confirmed cases.

The March reopening date is based on progress in vaccinating the most vulnerable groups in society by mid-February and then giving the jab time to take effect.

So far 7,164,387 people have received a first dose of either the Pfizer or AstraZeneca vaccines – a rise of 311,060 on the previous day’s figures –  although Mr Johnson acknowledged a “sense of frustration” about the patchy nature of the rollout.

The Prime Minister also set out tougher measures to prevent the arrival of new strains of coronavirus into the UK, confirming plans for a 10-day quarantine in hotels for travellers from high-risk countries.

In a Commons statement he said he would set out the Government’s strategy for the “gradual and phased” easing of lockdown in the week beginning February 22.

But with the reopening of schools only set to begin on March 8, easing of “economic and social restrictions” could only take place “then or thereafter”.

England’s schools are currently closed to all but vulnerable pupils and the children of key workers.

The Prime Minister told MPs: “The first sign of normality beginning to return should be pupils going back to their classrooms.”

But the UK remains in a “perilous situation, with more than 37,000 patients now in hospital with Covid – almost double the peak of the first wave”.

Mr Johnson acknowledged that the delay in reopening schools was “deeply frustrating” and “disappointing”.

Arrangements to provide free school meals for eligible pupils would be extended and an extra £300 million will be available for tutoring to help children catch up on missed lessons.

Referring to the 100,000 death toll, Mr Johnson said: “The most important thing we can do to honour their memory is to persevere against this virus with ever greater resolve.”

He urged people to “hold our nerve in the endgame of the battle” against coronavirus.

The Government has warned that the emergence of a vaccine-resistant new variant could throw its plans off track and Mr Johnson and Home Secretary Priti Patel set out plans for tougher controls on international travel.

The announcement on quarantine covers countries which are already subject to a travel ban due to concern over mutant strains of coronavirus, including South Africa, Portugal and South American nations.

“In order to reduce the risk posed by UK nationals and residents returning home from these countries, I can announce that we will require all such arrivals who cannot be refused entry to isolate in Government provided accommodation, such as hotels, for 10 days without exception,” Mr Johnson said.

“They will be met at the airport and transported directly into quarantine.”

Mr Johnson said the Government had been in contact with the devolved administrations on the issue so that “where possible we continue with a UK-wide approach” – but Scotland and Wales have both indicated they could go further.

The Home Secretary stressed that “going on holiday is not a valid reason” to ignore the stay-at-home rules as she strengthened enforcement measures.

People wishing to travel abroad will be required to make a declaration as to why they need to make the journey, which will be checked by carriers prior to departure.

“Every layer of protection we have put in place will help to reduce the risk of transmission of this virus and any new potential strain from entering the UK,” she said.

In other developments:

– The Archbishops of Canterbury and York urged people to take a moment each day to pause and remember the more than 100,000 people across the UK who have died after contracting Covid-19.

– Professor Neil Ferguson, a member of the New and Emerging Respiratory Virus Threats Advisory Group (Nervtag), said that if the Government had acted earlier and with “greater stringency” in September a lot of recent deaths could have been avoided.

– Professor Calum Semple, who sits on the Government’s Scientific Advisory Group for Emergencies (Sage), said there could be another 50,000 deaths from coronavirus before the pandemic “burns out”.

– Dr Richard Harling, director of health and care at Staffordshire County Council, said local authorities will be dealing with the virus “throughout the 2020s, into the 2030s”.

The current phase of the vaccination programme covers the top four priority groups, including people aged over 70, care home residents and frontline health and care workers, around 15 million people.

Mr Johnson said the Government was on target to meet the goal of offering them a first dose by February 15 “if we can get the supplies” of vaccine.

Labour leader Sir Keir Starmer called for teachers and key workers to be vaccinated once the four top priority groups defined by the Joint Committee on Vaccination and Immunisation (JCVI) had received the jab.

Under the existing plan, the JCVI’s next priority groups include all over-50s and people with underlying health conditions.

Mr Johnson said the JCVI list was designed to prioritise those most likely to die or suffer from coronavirus and Sir Keir “has to explain which vaccines he would take from which vulnerable groups” to give to key workers.

Sir Keir accused the Government of repeated failures, telling MPs: “To lose 100,000 people to this virus is nothing short of a national tragedy.”