Beefed-up rules will require travellers to stay in hotels near airports for 10 days, according to the Times and BBC.
Non-UK arrivals from the targeted destinations, which include South America, Portugal, Cape Verde and South Africa — are already barred following the discovery of two virus variants in Brazil and South Africa.
The 10-day quarantine will cost returning Britons £1 500 (R31 256) with meals served at the bedroom door and security guards supervising stays.
Interior minister Priti Patel is due to make a statement in parliament later on Wednesday on the borders policy after a meeting of the government’s Covid-19 operations committee.
Housing minister Robert Jenrick told Sky News the government would be taking “further steps… to ensure that there is less flow of individuals” returning but gave no further details.
The Times reported ministers were divided between those backing the limited quarantine regime and those favouring a blanket policy requiring arrivals from all destinations to self-isolate in hotels.
The main opposition Labour Party’s health spokesman Jonathan Ashworth said stricter border measures were long overdue and urged the government to consider a more comprehensive policy.
“There will be areas or countries across the world where there are mutations which haven’t been identified yet because they don’t have the same level of scientific ability,” he told the BBC.
Britain has been the hardest hit in Europe from the pandemic, becoming only the fifth country in the world to surpass 100 000 deaths after recording another 1 631 fatalities on Tuesday.
With a more contagious virus variant sweeping the country since December, some health experts have warned it could register as many as 50 000 further deaths in the coming months.
Prime Minister Boris Johnson imposed a third national lockdown in early January, shutting schools and non-essential shops, but critics have said the UK’s borders remain a soft spot.
The government earlier this month scrapped its “travel corridors” from countries with lower caseloads, and now asks all arrivals to show negative Covid-19 tests and then self-isolate.
Ministers have since been mulling whether to require all incoming travellers to isolate in hotels, emulating past actions taken by countries such as Australia and New Zealand which have emerged with dramatically lower death tolls.