The union called on German-based pilots to strike from Wednesday 0101 GMT until Thursday 0059 GMT, affecting all flights departing from Germany during that period.

"Despite the clear signal sent with the strike in early August there's still standstill at the negotiation table,"

Ingolf Schumacher, VC's pay negotiator, said in a statement.

Ryanair last month suffered its worst one-day strike after a walk-out by pilots in five European countries disrupted the plans of an estimated 55,000 travellers with the budget airline at the height of the summer holiday season.

More walk-outs are on the cards as seven trade unions representing Ryanair cabin crew in five countries threatened last week to hold a strike in late September unless the airline agrees to improve working conditions.

"Since we have already offered local contracts and improved pay there is no justification for further disruption and we are calling on our German pilots to work this Wednesday," Ryanair said in a written statement in response to VC.

The union said bargaining agreements with Irish and Italian pilots last month could not serve as blueprints for Germany because key questions on pay and working conditions had not been addressed.

VC said the airline had proposed an Irish national as mediator, who VC rejected because the person lacked "sufficient knowledge of German law".

(Reporting by Ludwig Burger; editing by David Evans, William Maclean)