Passengers with low-cost airline Easyjet are suffering delays after 19 flights in and out of Britain were cancelled.

The company blamed the move - which comes a week after passengers staged a protest sit-in at Nice airport - on crewing problems stemming from technical hitches with aircraft.

Crews caught up in the delays worked up to their maximum hours and then had to be allowed home to rest.

Saturdays in the summer, especially August, are the worst for air movement

Nats

Mobilising replacement crews has been a problem as it takes time to bring people to airports from home. Standby crews were already being used and other staff are on holiday.

The affected flights were all to or from a variety of European destinations on Sunday. They included two routes from Liverpool Airport and six from Luton.

Passengers booked on the 19 cancelled flights have been transferred to alternative services either on Sunday or Monday.

A Easyjet representative confirmed that 19 flights had been cancelled on Sunday, but was unable to comment on why this had been the case.

Thunderstorms

No more flights were expected to be cancelled, she added.

A spokeswoman for National Air Traffic Services said the problems were not due to any system failure.

"Thunderstorm activity and the sheer volume of traffic were to blame," she said.

"Yesterday was one of our busiest days of the year.

"Saturdays in the summer, especially August, are the worst for air movement."

Sit-in

A week ago more than 130 passengers staged a sit-in on an Easyjet flight in Nice bound for Luton.

The pilot asked them to switch planes just before take-off to allow people booked on another delayed aircraft to take their places.

The mechanical problem on the Paris-bound aircraft was eventually fixed, allowing both planes to fly to their original destinations.

Last month Easyjet's takeover of rival low-cost airline Go was approved by European regulators.