Deutsche Lufthansa AG’s pilots’ union is holding a vote on whether to strike, a move that would further disrupt the airline’s crucial summer travel season.

The VC pilots’ union is gauging support for a walkout as talks with the airline over pay and conditions stumble, according to a spokeswoman for the labor organization. A strike could then take place as soon as August, typically among the busiest months for the European travel sector. 

Lufthansa’s pilots will be able to go on strike if 70% of members vote in favor. Previous pilot walkouts have lasted several days, leading to thousands of cancellations and costing the company tens of millions of euros.

The aviation industry is bouncing back from the depths of the coronavirus pandemic, which forced Lufthansa into a government bailout and caused huge losses across airlines.

As passengers rush to board planes again for business trips and summer vacations, they’re confronted with chaotic scenes at airports that often lack sufficient staffing to manage the surge. In response, airlines have canceled flights and thinned out capacity to help manage the flow, often at short notice. Lufthansa has already canceled around 6,000 flights for the summer.

Lufthansa has dodged the crippling strikes endured by other airlines, but anger is brewing among employees who say they’ve borne the brunt of drastic cost cuts that they say put Lufthansa’s branding as a premium carrier at risk. 

Chief Executive Officer Carsten Spohr has pledged to boost earnings before interest and taxes to a minimum of 8% by 2024, a move he said was needed to reduce debt. Disputes with worker representatives suggest Spohr might have trouble reaching those goals, as he tries to balance the need for more staff with his desire for lower costs.

Still, the airline last week said it returned to profitability in the second quarter, benefiting from surging travel demand that’s forced the sector to raise fares and limit seat availability.