EasyJet cancelled more than 200 flights over the weekend with disruption expected to last into this week.
The airline blamed the problems on high levels of sickness among employees caused by Covid, with at least 222 trips axed since Friday.
The cancellations left some passengers stranded, amid travel chaos at some of Britain鈥檚 biggest airports.
EasyJet said it had made efforts to offset staff shortages by 鈥渞ostering鈥 additional standby crew on the weekend but was forced to make 鈥渁dditional cancellations for today (Sunday) and tomorrow鈥.
A total of 62 flights scheduled for Monday have been pulled, the majority of which were announced at short notice on Saturday.
An easyJet spokesperson said: 鈥淎s a result of the current high rates of Covid infections across Europe, like all businesses easyJet is experiencing higher than usual levels of employee sickness.
鈥淲e have taken action to mitigate this through the rostering of additional standby crew this weekend, however, with the current levels of sickness we have also decided to make some cancellations in advance which were focused on consolidating flights where we have multiple frequencies so customers have more options to rebook their travel, often on the same day.
鈥淯nfortunately it has been necessary to make some additional cancellations for today and tomorrow. We are sorry for any inconvenience this may cause to customers on affected flights.
鈥淲e have made 62 pre-emptive cancellations for flights to and from the 海角视频 for tomorrow which represents a small proportion of tomorrow鈥檚 total flying programme which was planned to be more than 1,645 flights.
鈥淲e cancelled the majority of these yesterday.鈥
Some holidaymakers told the PA Media news agency they had been left stranded abroad with no explanation or alternative route home offered by the airline.
It comes as passengers were stuck in long queues at Heathrow Airport on Sunday morning as the Easter holidays began.
The airport attributed the congestion to Covid checks required by destination countries and 鈥渉igh passenger volumes鈥.
But there were also reports of staff shortages and problems with the e-gate passport checkpoints as travellers took to social media to air their frustrations, with some saying they had waited hours to take off.
Other travellers said several of the automatic e-gates, staffed by Border Force and used to process passengers, were not operating properly.
The Home Office confirmed there had been a 鈥渢echnical issue鈥 with the checkpoints which has since been resolved, and said the problem had not caused queues to exceed the 鈥渟tandard length鈥 at Heathrow.
But a Heathrow spokesperson said: 鈥淒ue to high passenger volumes and the Covid documentation checks still required by many end destinations, Terminal 2 departures has experienced some congestion today.
鈥淥ur teams are supporting our airline partners to get passengers away on their journeys as quickly as possible and we apologise for any inconvenience this has caused.鈥
Manchester Airport has experienced similar problems in recent weeks as it has struggled to cope with delays due to increased traveller numbers amid staff shortages.
Some travellers landing also voiced complaints about extensive waits in the baggage reclaim halls.
A spokesman for Manchester Airport said passengers were being advised that 鈥渟ecurity queues may be longer than usual鈥 and urged to arrive early for their flight.
鈥淲e apologise to passengers whose experience at Manchester Airport has fallen short of the standards they expected.
鈥淎s we recover from the impact of the coronavirus pandemic, our whole industry is facing staff shortages and recruitment challenges.鈥
They added: 鈥淲e are aware similar challenges are being faced by airlines and third parties, such as baggage handling agents, operating on our site.鈥
Like this story? Why not sign up to get the latest South West business news straight to your inbox.
