KLM ground staff will go on a 24-hour strike on June 28 in support of their pay claim because talks with the employers have stalled, unions FNV and CBV said on Tuesday.

The unions say workers are “livid” because the airline is not contemplating any pay rise at all. The FNV is also demanded higher compensation for employers who do hard physical labour.

The Dutch flag carrier said in a letter to the unions the strike is “totally disproportionate” and damaging to the company, particularly “given the current difficult financial situation” facing the company. The airline has not ruled out legal action if the strike goes ahead.

Union official John van Doorland said he would only return to the negotiating table if KLM at least offers a pay rise in line with inflation. “We want to maintain spending power. KLM compensates pilots very generously. It is incomprehensible it is not doing the same for ground staff,” he told broadcaster NOS.

KLM told the unions the company is “in the middle of a battle for a healthy future”, with higher fuel costs, airport fees and the loss of routes due to armed conflicts depressing revenue. The company urged everyone to “roll up their sleeves” in a time of crisis.

The strike will start at 2 am on Saturday June 28 and end at 2 am on Sunday. KLM expects some flights to be cancelled if the strike goes ahead. The FNV said further strike action may follow.