Heathrow has said Covid-19 continues to pose “significant challenges” for the travel industry as the airport reports results for 2021. The London airport welcomed just 19.4 million passengers last year, less than one quarter of the figure seen in 2019 and below even 2020 levels.

At least 600,000 passengers cancelled travel plans from Heathrow in December due to Omicron and the uncertainty caused by swiftly imposed government travel restrictions, the airport added. The cancellations were part of a wave of groundings last month, with new data showing for flights were cancelled in December than during any other month last year. Heathrow said “significant doubt” remained over the speed at which demand in the aviation sector will recover.

IATA forecasts suggest passenger numbers will not reach pre-pandemic levels until 2025, provided travel restrictions are removed at both ends of a route and passengers have confidence they will not return rapidly.

Heathrow chief executive, John Holland-Kaye, said: “There are currently travel restrictions, such as testing, on all Heathrow routes – the aviation industry will only fully recover when these are all lifted and there is no risk that they will be reimposed at short notice, a situation which is likely to be years away. While this creates enormous uncertainty for the CAA in setting a new five-year regulatory settlement, it means the regulator must focus on an outcome that improves service, incentivises growth and maintains affordable private financing.”

Kaye urged the UK government to remove all testing for fully vaccinated passengers now and to adopt a playbook for any future variants of concern that is more predictable, limits additional measures only to passengers from high-risk destinations and allows quarantine at home instead of in a hotel.