The government is expected to announce that some travellers coming to England will have to quarantine in hotels, over concerns about new Covid variants.
Prime Minister Boris Johnson will make a decision after discussing the proposals with senior ministers later.
The new measures are likely to apply to UK citizens and those with permanent residency rights arriving from high-risk countries such as South Africa.
Most foreign nationals from high-risk countries already face UK travel bans.
The new requirement to isolate in a hotel for 10 days will apply to arrivals from most of Southern Africa and South America, as well as Portugal, because many flights from Brazil come via Lisbon, according to BBC Newsnight’s political editor Nicholas Watt.
He said there had been “no definitive decision yet” on arrivals from other parts of the world and this was “still a live issue”.
Whitehall sources said those quarantining in hotels would have to pay for the costs of their own accommodation.
Prime Minister Boris Johnson will chair a meeting of the Covid operations committee attended by senior ministers later to discuss the options for new border controls.
However, it will not be possible to implement any new measures immediately, said BBC political correspondent Iain Watson.
Some ministers – including Home Secretary Priti Patel – have been pushing for more widespread use of hotel quarantine, arguing that too targeted an approach may prove ineffective, our correspondent reports.
Hotel quarantine is already in place in countries including New Zealand and Australia.
Under current travel curbs, almost all people must test negative for Covid-19 up to 72 hours before travelling to be allowed into the UK.
Even after this negative test, arrivals still have to quarantine for up to 10 days, although this can be done at home.
In England, this self-isolation period can be cut short with a second negative test after five days.
Quarantine rules are set separately in England, Scotland, Wales and Northern Ireland – but have only tended to differ slightly.
On Monday, Scotland’s First Minister Nicola Sturgeon confirmed officials around the UK had discussed a “four nations” approach to the issue.
She added that hotel quarantine was “under active consideration” by Scottish ministers, and would be discussed at a cabinet meeting on Tuesday.
The Northern Ireland Executive is also expected to discuss travel rules when it meets on Tuesday.
In Australia, travellers are allocated a hotel room on arrival and taken there by bus. Often, entire flights are accommodated in the same hotel.
The New South Wales government pledges to make “every attempt” to find suitable accommodation for travellers and families. But availability of rooms means there are severe limits on the number of people who can arrive into the country on any given day.
The hotel quarantine lasts a minimum of 14 days up to 24 days, providing a person tests negative twice.
The cost of the quarantine is borne by the passenger – at around £1,700 per adult and £2,800 for a family of two adults and two children – and billed after the quarantine in completed.
Fees are waived for those who can prove they are unable to pay, and there are certain exemptions.
But not following the rules is a criminal offence, and in New South Wales carries fines of around £6,000 for individuals, six months in prison, or both with an additional £3,100 fine for each day the offence continues.
Joss Croft, chief executive of UKinbound, which represents the interests of the country’s tourism sector, said he hoped the hotel quarantine rules would cover as few countries as possible,
He told the BBC’s Newsnight that the industry had been “decimated” and the new measures were “the last thing we need”.
“We’ve got to start thinking once these conditions are put in then how are we going to wind our way back from that,” he added.
In a joint statement, the Airport Operators Association and Airlines UK said the country already had “some of the highest levels of restrictions in the world” and that introducing tougher rules would be “catastrophic”.
On Monday, Mr Johnson said ministers were “actively working” on the idea of quarantine hotels.
He said the UK already had “one of the tightest regimes in the world” but the government wanted to “protect this country from reinfection from abroad” and the spread of new variants during the rollout of vaccines.
The policy is among the measures credited with limiting cases of coronavirus in Australia – whose population is around 25 million – to just 28,777 positive cases during the entire pandemic.
This is a smaller number of new cases than are currently recorded in the UK every day – with a daily average of over 33,000 in the past seven days.
Ministers have been facing pressure to toughen up the UK’s borders in recent weeks, with Labour accusing ministers of “dragging their feet on setting vital protections”. The party’s shadow home secretary Nick Thomas-Symonds has backed the idea of using hotels to help “prevent the importation of further strains of the virus”.
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