Ryanair Holdings Plc’s cabin crew may go on strike this summer in several European countries after the continent’s largest low-cost airline walked away from talks with two Spanish unions.

The impasse over issues including higher pay leaves “no other option” but to call for a walkout, a representative of the SITCPLA labor group said in a response to questions. “We’re coordinating our actions with European counterparts.”

SITCPLA and fellow Spanish union USO have joined forces with five workers’ organizations in Belgium, France, Italy and Portugal to prepare Europe-wide actions if the Irish company doesn’t come to the table. That could jeopardize the carrier’s recovery from the coronavirus pandemic at the peak of this summer’s high season, when travel demand is expected by many airlines to at least come close to 2019 levels. 

A walkout would also exacerbate turmoil that’s already engulfed European airports as staff shortages and supply chain issues lead to lengthy queues and cancelled flights. 

Ryanair called off talks in Spain after the unions began to threaten a strike, according to a letter from airline director Darrell Hughes seen by Bloomberg News. Negotiations on a collective agreement “almost made no progress” due to the unions’ “unrealistic demands and refusal to meaningfully engage,” the carrier said.

Ryanair didn’t immediately respond to a request for comment. 

The proposals sent by USO and SITCPLA included “up to 167% pay increases at a time when Covid recovery is still fragile and the company is still announcing significant losses,” the letter said.