A requirement to stay in quarantine hotels is expected to be limited to Britons returning from 30 ‘high-risk’ countries covered by a travel ban on foreigners.

The government was poised to announce mandatory hotel quarantine for arrivals today (Wednesday) to combat new Covid variants as the UK death toll from the virus passed 100,000.

The hotel quarantine restriction will not amount to a blanket rule for all travellers – meaning it would apply to southern Africa, South America and Portugal owing to the volume of traffic from Brazil via Lisbon.

It means that any of an estimated 345,000 Britons living or working in the 30 countries would have to quarantine in government-approved hotels at their own expense if they returned to the UK.

An announcement is expected following a meeting of the government’s coronavirus operations committee on Tuesday evening.

Home secretary Priti Patel is due outline details in the House of Commons later today, including the timescale for the policy and who will be exempt.

New analysis by the World Travel & Tourism Council found that hotel quarantine measures could wipe out almost £550 million a day from the UK economy in lost business, family and leisure travel.

Bosses of major UK airlines warned that there is not enough evidence to support a blanket quarantine in hotels in addition to tougher recent travel restrictions.

A letter to Boris Johnson signed by the heads of British Airways, Virgin Atlantic, easyJet, Tui, Jet2, Loganair and industry body Airlines UK warned that even at current levels restrictions were having a “dramatic impact” on the industry and wider economy.

They joined wider industry calls for a plan for the easing of rules ahead of the crucial summer peak.

“With the latest lockdown, travel ban and now prospect of hotel quarantine, the time has now come for a bespoke support package that can get UK airlines through this crisis, and a roadmap out of these restrictions… including testing, working in concert with vaccine rollout,” the letter, reported by Sky News, said.

The prime minister confirmed on Tuesday: “Looking at hotels is one thing [we’re working on]. We need the maximum possible protection against reinfection from abroad.”

Arrivals will be directed to a hotel and confined for 10 days, then have to pay the bill.

An aviation source told Travel Weekly: “We’re not sure how this will work. We expect Border Force to organise it, but there is a big question around enforcement.”

An airline source added: “It’s an extreme measure, but if restricted to countries with travel bans in place it can work. It doesn’t seem scalable. Do we have the hotel capacity to extend something like this?”

An obvious limitation is the number of hotel beds sufficiently near to Heathrow to make the system work. But the source added: “We have to know the pathway out of this.”

The aviation source agreed: “There has to be a clear pathway out, but it’s unclear what that pathway looks like and whether the government will provide one. They keep layering on restrictions and we get very little response to calls for a pathway out. The government bandwidth for thinking about this does not seem to be there.”

A senior leisure industry source warned: “The government has taken all the pain it’s going to get over lockdown and the public is probably behind them. People are saying ‘Why isn’t the industry screaming about this?’ But the industry would be flying in the face of its customers.”

A YouGov poll found 87% of UK adults in favour of making travellers quarantine in hotels for 10 days on arrival. Almost two in three (64%) backed a ban on international flights.

Patel declined to comment in advance of the announcement, but told MPs on Tuesday: “Policy is being developed.”

Asked how long the new measures might be in place, she said: “We keep all measures under review. We’ve seen escalation and de-escalation. Now we see an escalation, but these measures will be kept under review.”

Patel confirmed “crowded scenes” at Heathrow at the weekend were due to “the checks Border Force put in place” to ensure all arrivals have pre‑departure Covid test results and said: “Border Force is now checking 100% of arrivals.”

The aviation source said: “People are waiting three hours at Heathrow. You only need 100 people to have a 200-metre queue with social distancing. Border Force is not sufficiently staffing this. But it’s not a problem at any other airport.”

Diana Holland, assistant general secretary of the Unite union, said: “The government’s intention to introduce quarantine hotels for some passengers may assist with its public health challenges but it cannot be introduced without recognising this is a further blow to the aviation sector.

“We have no idea how long the policy will be in place or whether its scope may need to be extended in the future.

“While such policies are in place the aviation sector will face a sustained delay in recovery.

“The aviation industry, its workers and the communities who rely on it are crying out for the government to come forward with a joined-up approach to protect jobs, airports and routes.

“The government first promised sector-specific support over 10 months ago and it has so far failed to deliver.

“With the furlough scheme set to end in the spring, unless the government steps in soon thousands of more jobs are set to be needlessly lost.

“Once the most intense impact of the pandemic is over, the aviation industry, which is critical for the UK’s connectivity and economic success, will quickly begin to recover. But it will only do so if the government provides the support aviation needs in order to survive this crisis.”