The majority of Lufthansa flights scheduled for today have been cancelled due to a strike over pay.

The German airline said only about 20 of its flights would run as planned, out of more than 1,700 originally scheduled.

Lufthansa warned passengers to expect “massive” flight cancellations and delays that started to affect long-haul flights from yesterday. The airline is offering free alternative bookings.

Flights to and from London, Manchester, Birmingham, Newcastle, Glasgow, Dublin, Aberdeen and Edinburgh will be hit. German airports affected are Frankfurt, Munich, Dusseldorf and Hamburg.

The carrier said the industrial action, the second in the last two months, was uncalled for.

“It’s completely out of proportion,” a Lufthansa spokesman was quoted as saying by the Reuters news agency. “Especially given that four further dates for pay talks had already been agreed upon.”

Ground staff called the one-day strike amid an ongoing pay dispute with the airline. Lufthansa last week rejected union demands for a 5.2% wage increase over the next 12 months. Strikers are also looking for guarantees over job cuts.

Unions staged a similar one-day strike last month. Short “warning strikes” are a common tactic among German unions, designed to put pressure on wage negotiations.