Heathrow on Tuesday said the number of passengers passing through London's main airport dropped more than 12 percent last year, with the Omicron coronavirus variant stalling recovery prospects.
"Covid-19 continues to pose significant challenges for the travel industry," Heathrow said in a statement.
The airport welcomed 19.4 million passengers last year -- less than one quarter of the level in 2019 before the pandemic struck.
Passenger numbers dropped 12.3 percent compared with 2020.
Heathrow said that at least 600,000 passengers cancelled travel plans from the airport in December owing to "Omicron and the uncertainty caused by swiftly imposed government travel restrictions".
The airport, mirroring a plea by airlines, urged the British government to immediately remove all testing for fully vaccinated passengers.
"There are currently travel restrictions, such as testing, on all Heathrow routes," the airport's chief excutive John Holland-Kaye said in Tuesday's statement.
"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."