After nearly five years of contract negotiations, flight attendants at Sun Country Airlines have authorized a strike to put more pressure on the Minneapolis-based airline to speed up the process.

The union representing about 560 Sun Country flight attendants — Teamsters Local 120 — said Thursday that 99% of the attendants eligible to vote cast a vote in favor of the strike.

"We voted to strike for one simple reason," Tanya DeVito, a flight attendant and member of the union's bargaining committee, said in a statement. "Sun Country is dragging out the negotiation process, and we are fed up. We are fighting for the contract we deserve."

The flight attendants have been working under a 2014 contract that was amended in 2016. The airline and union have been negotiating a new contract since 2019, when the collective bargaining agreement became fully amendable. In 2023, attendants rejected a tentative agreement, with 96% voting down the deal.

Under federal law, because it involves airlines, several steps must be completed before a strike can take place, including this week's authorization vote. The union also must notify the public and gain approval from the federal government.

Union officials previously said wages for Sun Country flight attendants start at $21.53 an hour and can reach $53.56, but only for those with more than 30 years of experience. Yet the top pay rate for attendants at the airlines is still 19% lower than that of other low-budget carriers, including Frontier and Spirit Airlines, union officials said.

Frontier flight attendants this month voted to authorize a strike of their own.

"We expect a solid economic package to be brought to us at September's mediation session, or we will take this to the next level," DeVito said.

Sun Country said the strike authorization won't affect its passengers.

"We appreciate our flight attendants and everything they do for Sun Country's customers and our airline. We respect their right to express themselves through this vote," the airline's leadership said in a statement.

Sun Country and the union are negotiating a new contract with the help of the National Mediation Board. If the board determines the parties can't reach an agreement, it will issue a proffer of arbitration — an offer to enter binding arbitration to end the dispute.

If either side rejects the proffer, the mediation board will release the airline and union into a 30-day cooling-off period. From there, the union can strike or Sun Country can lock out the workers.

Sun Country officials said in their statement that they are confident an agreement will be reached. The airline's pilots approved a new contract in December 2021 that gives them a significant pay increase. Its fleet employees and mechanics also voted to unionize in recent years.

Sun Country employs more than 2,500 people; most are based in Minnesota.