Boris Johnson said on Sunday they would be imposed on people arriving by air into the UK, to prevent Covid-19 being brought in from overseas.

Mr Johnson said he was "serving notice" that quarantine measures were coming.

Following his speech, No 10 confirmed a reciprocal deal with the government in Paris meant restrictions would not apply to passengers from France.

The prime minister said: "I am serving notice that it will soon be the time - with transmission significantly lower - to impose quarantine on people coming into this country by air."

UK airlines previously said they had been told that any quarantine period would last for 14 days, and that people might be expected to provide an address when they arrive at the border.

Government sources had already indicated that people arriving from the Republic of Ireland would not have to self-isolate when the quarantine measures take effect.

'Growing crisis' for aviation

Despite speaking to the aviation minister on Sunday, airline and airport bosses told the BBC that they were still in the dark over basic details such as when the quarantine measures would come into force, when they would end and whether they would be continuously reviewed.

Airlines are calling for additional government support after the prime minister confirmed a quarantine period will come into force.

Airlines UK chief executive Tim Alderslade said: "We all, including government, need to adapt to the new normal, but closing off air travel in this way is not the way to achieve this.

"Ministers are effectively telling people they can no longer travel for the foreseeable future and airlines will respond to that by grounding their operations."

He added: "That is why they require urgent additional government support to get through this growing crisis."

Air travel has ground to a halt because of the global coronavirus pandemic, prompting steep jobs cuts by the industry.

Ryanair has said it planned to axe 3,000 workers and ask remaining staff to take a pay cut.

BA previously said it would cut 12,000 of its workforce and warned that it may not reopen at Gatwick Airport once the pandemic passes.