Britain intends to seek a "cautious but irreversible" ending of strict coronavirus restrictions, Prime Minister Boris Johnson said Monday as his government introduced hotel quarantine stays for arrivals from "high risk" nations.

Britain, with more than 117,000 deaths from Covid-19, is one of the worst-hit countries in the world by the pandemic. Johnson has come under criticism for acting too quickly to relax measures and too slowly to re-impose them in recent months.

But lockdown-sceptical MPs are pressing for an accelerated exit after Britain over the weekend surpassed its target to vaccinate 15 million of the most vulnerable people with a first vaccine jab.

Speaking at a health clinic in southeast London, Johnson said the government needed to be "very prudent" as it reviewed a third stay-at-home order in England that has shut down schools, non-essential businesses and hospitality venues since early January.

"What we wanted to see is progress that is cautious but irreversible, and I think that's what the public and people up and down the country will want to see," Johnson said.

The government is due to set out a roadmap to relax the measures in England on February 22, and has indicated schools could reopen on March 8.

However, Health Secretary Matt Hancock said there is "some way to go" before lockdown can be eased, stressing the government was awaiting key data on how successfully the vaccines reduce transmission.

But over the weekend, more than 60 MPs from the ruling Conservatives signed a letter calling for Johnson to commit to a firm timetable ending with the lifting of all legal controls by the end of April.

Once enough people are inoculated, "it's time for us to take a bold stride into life and start to recover our society and our humanity", lawmaker Steve Baker told Talkradio on Monday.

Red list

While eyeing a possible route out of lockdown, the government is also tightening the borders to guard against emerging variants of the coronavirus that could undermine the vaccination programme.

The new quarantine policy requires all UK citizens and permanent residents entering England from 33 "red list" countries to self-isolate at their own expense in approved hotels for 10 days and take several Covid-19 tests.

Other visitors from the countries, including all South American nations, South Africa and Portugal, are currently barred from visiting the UK.

Arrivals found to have given false information about being in one of the countries 10 days before travel could receive up to 10 years in prison -- which has drawn criticism for being excessive.

The government says it has signed contracts with 16 hotels so far, securing nearly 5,000 rooms near English airports, with a further 58,000 rooms on standby, as it belatedly follows the example of others such as Australia and New Zealand.

Hancock said the government had resolved initial problems with the new policy at Heathrow Airport, Britain's busiest aviation hub.

"We've been working with the airport and with the Border Force to make sure everybody knows the process," he told Times Radio. 

"And it does appear to be going smoothly this morning," he added.

The 11-night quarantine costs £1,750 ($2,420, 2,000 euros) for transport, food, accommodation, security and testing.

Passengers must have a negative Covid-19 test result from within three days of travel, and book and pay for the package before setting off for Britain.

They will then take further tests on the second and eighth days of their stays.

The hotel occupants will be able to leave their rooms only in "very limited circumstances", with exercise requiring "special permission" from staff or security. 

Anyone refusing to take tests risks a fine of between £1,000 and £2,000, while those who do not self-isolate could have to pay between £5,000 and £10,000.