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.