Starting from Monday, British nationals arriving from 33 high-risk countries will have to quarantine for 10 days at home or in a government-approved hotel.

However, Heathrow Airport warned on Saturday that the hotel quarantine plan is not yet ready for launch. “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,” the airport said in a statement.

It urged ministers to ensure there is “adequate resources and appropriate protocols” for all transfers from aircraft to hotels, which would “avoid compromising the safety of passengers and those working at the airport.”

The statement comes a day after head of the UK Parliament’s Home Affairs Committee, Yvette Cooper, said that “chaotic long queues with no social distancing” could trigger super-spreading events. The worrying signs also emerged after the booking website for the hotel quarantine scheme crashed minutes after going live on Thursday.

Officials decided to tighten border controls due to fears of more contagious coronavirus variants coming from overseas, which could undermine the ongoing vaccination campaign. Cases of the South African variant have already been reported in Britain, as the country battles its own more transmissible coronavirus mutation, known locally as the ‘Kent variant’ and the ‘UK variant’ globally.

Prime Minister Boris Johnson, meanwhile, asked the public for “more time” to analyse the effects of the vaccination on the infection dynamic. “I’m optimistic, but we have to be cautious,” he told reporters on Saturday.