Heathrow Airport has said “significant gaps” remain in the hotel quarantine plan with less than 48 hours before the scheme begins.
UK nationals or residents returning to England from 33 countries will be required to spend 10 days in Government-designated accommodation from Monday.
But a spokeswoman for Heathrow said they are yet to receive the “necessary reassurances” from the Government.
A statement from the west London airport said: “When the Government announced its hotel quarantine plan, we immediately offered our help to make this successful in a complex airport environment.
“We have been working hard with the Government to try to ensure the successful implementation of the policy from Monday, but some significant gaps remain and we are yet to receive the necessary reassurances.
“We will continue to work collaboratively with Government over the weekend but ministers must ensure there is adequate resource and appropriate protocols in place for each step of the full end-to-end process from aircraft to hotel to avoid compromising the safety of passengers and those working at the airport.”
One of the Heathrow Airport hotels taking part in the scheme is Novotel London Heathrow T1 T2 T3.
The hotel was charging £65 for members of the public staying on Sunday night, while travellers using it to quarantine from Monday must pay £1,750 for 10 days.
The PA news agency understands that the Renaissance London Heathrow Hotel is also participating in the programme.
A Government spokeswoman said: “We are taking decisive action at the borders and every essential check – from pre-departure testing to the Passenger Locator Form – will help prevent the importing of new coronavirus variants into the UK.
“We are working closely with airports and hotels to manage any issues that arise and ensure the new process runs as smoothly as possible, and we are clear the safety of all staff and passengers is a priority.”