(Bloomberg) -- Southwest Airlines Co. flight attendants overwhelmingly rejected a contract proposal that would have provided an immediate 20% pay increase, 3% annual boosts through 2028 and a ratification bonus.

The agreement was voted down 11,761 to 6,635, Transport Workers Union local 556 said in a livestream on its website Friday. The union didn’t comment on any particular reason for the rejection, which does not give workers the ability to strike.

“The flight attendants of Southwest Airlines have made it clear that this proposed contract is not going to heal the hurt,” Lyn Montgomery, TWU 556 president, said in a statement. “We will go back to the table to achieve the collective bargaining agreement that meets the needs of the hardest-working flight attendants in the industry.”

In a video posted on Facebook, the union’s negotiating committee said “nothing’s going to happen over the holiday season,” and that they are seeking dates to continue negotiations. 

The employees will continue to work under their current contract and “we’ll await the next steps from the National Mediation Board and TWU 556,” Southwest said in a statement. The NMB has been overseeing negotiations.

The vote adds to heightened tensions in the industry as some carriers rake in record revenue on the post-pandemic travel rebound, while workers seek higher compensation and quality-of-life improvements including more flexible schedules. Flight attendants, pilots and other workers have frequently picketed outside of company meetings and offices and at airports this year. 

TWU 556 members’ rejection of the tentative contract follows a June vote by union leaders who also turned down a prior pending agreement its negotiators had reached with the carrier. Flight attendants are working under pay scales and rules that were part of a 2016 contract. 

The rejected agreement would have provided paid maternity, parental and extended “bonding leave,” all with insurance coverage, items the union described as a first for flight attendants at a US carrier. It would have ended 24-hour on-call reserve shifts, replacing them with three 12-hour shifts, and increased reserve pay, boosts per diem and double time pay for work on Memorial Day and July 4.

Negotiations continue with flight attendant unions at United Airlines Holdings Inc. and American Airlines Group Inc. A federal oversight board recently rejected a request by the Association of Professional Flight Attendants to find talks with American stalled and allow the union to move a step closer to a possible strike.

Southwest and the union for its pilots are close to finalizing a tentative agreement, the Southwest Airlines Pilots Association has said. Pilots at American, United and Delta Air Lines Inc. all have reached new multibillion-dollar contracts this year. 

(Updates with union and company comments from fourth paragraph)

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