Budget airline easyJet cancelled more than 100 flights Tuesday due to severe weather conditions, in a fresh blow to European passengers hoping to travel for the Christmas holidays.
British Airways and Irish low-budget carrier Ryanair also warned of delays and cancellations due to the heavy snow and freezing temperatures, which have already caused chaos on the roads and suspended Eurostar train services.
EasyJet said disruption caused by "significant snowfall" had been exacerbated by airport closures, and warned that none of its flights would leave London Luton airport until 11:30 am (1130 GMT).
Luton, north of the British capital, had been closed overnight but reopened early Tuesday morning.
All flights were cancelled at Milan Malpensa airport, which was expected to stay closed until midday (1100 GMT), the airline added.
It also warned of "severe disruption with numerous cancellations" at London Gatwick, Rome Fiumincino, Madrid and Paris Charles de Gaulle airports.
"EasyJet sincerely apologises to those who have been affected by the disruption caused by such exceptional circumstances, and would like to reassure passengers the airline is doing everything possible to minimise the delays and cancellations and get them to their destination as soon as possible," it said.
BA said the majority of its flights were operating on Tuesday but there had been some "short-haul cancellations this morning due to the knock-on effect of the weather disruption yesterday".
Ryanair also warned that its flights were "subject to delay and possible cancellation", but urged passengers to check-in as normal.
Britain endured another night of below freezing temperatures, with thousands of people trapped in their cars overnight Monday. Forecasters at the Met Office national weather service issued severe weather warnings across the country Tuesday.
However, all the main airports remained open and Eurostar trains between London and continental Europe resumed a limited service after a three-day shutdown caused by weather-related breakdowns in the Channel Tunnel.