The Air Line Pilots Association announced pilots at Delta Air Lines voted to authorize union leaders to call a strike. According to Monday’s announcement, 96% of Delta pilots took part in the vote, and 99% of those favored calling a strike “if necessary” to get a new contract.

“Delta’s nearly 15,000 pilots sent a clear message to management that we are willing to go the distance to secure a contract that reflects the value we bring to Delta Air Lines as frontline leaders and long-term stakeholders,” Delta Master Executive Council Chair Capt. Jason Ambrosi said in a statement. “Our goal is to reach an agreement, not to strike. The ball is in management’s court. It’s time for the Company to get serious at the bargaining table and invest in the Delta pilots.”

Airline unions are seeking big pay increases and could have leverage because of labor shortages during a rebound in travel following the COVID-19 pandemic. Delta pilots are working under pay rates set in 2016.

“Delta has rebounded from the pandemic and is poised to be stronger than ever, posting record revenues for the third quarter,” Capt. Ambrosi said. “Meanwhile, our negotiations have dragged on for too long.”

Delta said the vote would have no impact on its flight operations. The airline added it has made significant progress in talks, that only a few contract sections are unresolved and it expressed confidence in reaching an agreement.

Even if an agreement between Delta and the union can’t be reached, pilots would have a couple legal hurdles to clear before they can strike. That is because by federal law, labor contracts in the airline industry do not expire.

Before workers can legally strike, federal mediators must determine that more talks would be pointless. Even after that, the president and Congress can intervene to block a strike.

Monday’s vote comes just days after American Airlines offered its pilots 19% pay increases over two years. It’s an offer that could serve as the model for talks at Delta and United Airlines. Leaders at American’s union have not decided whether to send the offer to a ratification vote.

The Associated Press contributed to this report.