Airlines fear any lack of rooms under the quarantine hotels scheme could force them to leave travellers stuck abroad.
It is understood ministers are considering adding a section to passenger locator forms, which all must fill out before departure. It could ask them if they have booked into a quarantine hotel in the UK.
But it is unclear whether carriers will be expected to bar travellers who answer no, leaving them stranded.
Health Secretary Matt Hancock will announce today that the Government has struck its first deals with hotel chains to accommodate those quarantining.
It is understood ministers are considering adding a section to passenger locator forms, which all must fill out before departure. It could ask them if they have booked into a quarantine hotel in the UK
Ministers are expected to unveil a booking system for travellers this week.
But an aviation source said yesterday: ‘We’re completely in the dark. We don’t know yet whether the Government will want us to deny boarding.’ Airlines are legally required to check passenger locator forms have been completed. They also have to check that a passenger has a negative Covid test taken within 72 hours of travel.
Ministers have been accused of being too slow to bring in quarantine hotels. The policy was announced in the Commons on January 27 but does not come into force until Monday.
Under the rules, hotels will have to provide three meals a day for guests for 11 nights. Travellers will be tested twice, on the second and eighth day of their stay.
Security guards will be stationed on each floor and by entrances and exits, with police on standby if passengers try to abscond.
But Heathrow airport has raised concerns about how the new scheme will work at borders.
A spokesman said: ‘Now that the Government has set a date, ministers need to work with industry to establish how this policy will actually be implemented at the border.
‘Our offer to support remains, but time is ticking and this very complex initiative requires airports, airlines and the Government to work closely together for it to be workable.’
Lucy Moreton, professional officer at the Immigration Services Union, which represents border staff, said border guards were yet to receive any fresh guidance about how the policy will work.
Health Secretary Matt Hancock will announce today that the Government has struck its first deals with hotel chains to accommodate those quarantining
She said: ‘We’ve heard absolutely nothing yet. You can’t rule out that the airlines would be asked to enforce it, but it would require a change to legislation and that isn’t easy.
‘From a Border Force perspective it would be magnificent if the airlines were responsible for that because it would reduce the checks we’re having to do at the border.
‘This is all likely to be honesty-based though. Short of us physically getting off the arrivals desks and phoning the hotels to check that those individuals have booked into them, we have no way of confirming.’