Airlines must operate more flights in Britain this summer as demand recovers from the pandemic - or lose lucrative take-off and landing slots, the UK government warned Monday.
Carriers operating in Britain are currently using about 50 percent of their slots as the sector continues to recover from the long-running Covid crisis.
This has helped to ensure that airlines have avoided carbon-intensive "ghost flights" - with none or few travellers during pandemic restrictions.
Carriers operating in Britain have traditionally been required to use 80 percent of their slots, but the target was suspended owing to Covid.
From the end of March, carriers must use slots at least 70 percent of the time in order to keep them, the Department for Transport (DfT) said in a statement on Monday.
But airlines will also "benefit from added flexibility over when they are justified not to use them", the DfT said.
During the pandemic, the rule had been eased "to provide financial stability to the sector and prevent environmentally damaging ghost flights", added aviation minister Robert Courts.
"As demand for flights returns, it's right we gradually move back to the previous rules while making sure we continue to provide the sector with the support it needs."
Monday's news was welcomed by London airports.
The move "strikes the right balance between driving recovery and promoting competition", said a Heathrow spokeswoman.
The aviation sector was slammed by the Covid-19 health emergency that erupted in early 2020, grounding planes worldwide and decimating demand for air travel.
Recovery has been hampered by frequent changes to travel restrictions and testing requirements following the emergence of the Omicron variant late last year.
British Prime Minister Boris Johnson on Monday said the government is set to drop compulsory coronavirus tests for fully vaccinated passengers arriving in England.
"To show that this country is open for business, open for travellers, you will see changes so that people arriving no longer have to take tests if they've been vaccinated," he told reporters on a hospital visit.
Johnson did not specify a date for the change. He noted that this will apply only to arrivals who have been "double vaccinated".
The government announcements failed to lift the sector, however, as share prices continued to be slammed Monday by worries regarding the impact of decades-high inflation on economic recovery.
IAG, owner of British Airways, slumped 6.5 percent by the close, while EasyJet shed 5.3 percent.