The CAA revealed on Tuesday (27 April) it had issued 630 fines in total since 11 February, and reminded carriers of their obligation to ensure passengers have the right documents before they arrive in England by air.

These include proof of a negative test for Covid-19, taken no more than 72 hours prior to departure, and a completed passenger locator form (PLF).

Airlines face fines of £2,000 for each passenger arriving without a valid pre-departure test certificate, and a further £2,000 for these who have not completed their PLF.

Additionally, airlines can be fined £4,000 for failing to provide the correct information to passengers before departure, and during their journey, informing them of their requirements.

There is also a £2,000 fine for conveying passengers who have been in a "red list" country in the previous 10 days to a non-designated port of entry.

Those returning to England from red list countries must arrive into Heathrow, Gatwick, London City, Birmingham, Bristol or Farnborough airports where there are provisions for government-approved hotel quarantine.

With Border Force checking all arrivals, there have been reports of six-hour queues to clear the border at Heathrow.

Earlier this month, Immigration Service Union (ISU) professional officer Lucy Moreton told Sky News there were still entire flights arriving without the correct paperwork.

She said non-compliance, and/or failure to have the correct documentation to hand, frequently pushed per-passenger delays beyond an hour, exacerbating the delays at the border.