A German cabin crew union has called on its members to walk out on all Lufthansa flights from tomorrow.

The announcement marks an escalation between the UFO union and the airline in a dispute over transition payments.

The airline confirmed that all of its flights from Germany would be affected from 4am (0300 GMT) tomorrow until midnight Friday (2300 GMT).

The strike began on Friday at Germany's three main airports, with tens of thousands of passengers affected so far by hundreds of cancellations.

UFO wants to secure transition payments for its 19,000 members if they retire early, among other demands as part of its contract dispute with Lufthansa, which is trying to cut costs.

The union rejected the airline's latest offer on Monday, saying it constituted only a "minimal" improvement. UFO representatives noted today that the airline recently increased its pre-tax earnings forecast for the year.

Flights operated by Lufthansa subsidiaries such as Germanwings, Swiss and Austrian Airlines will not be affected.