There’s no word yet on when Southwest Airlines can expect its flight attendants to walk off the job—but the likelihood is much stronger following an overwhelmingly pro-strike vote this week.

About 98% of voting members voted to go on strike, Transport Workers Union Local 556 reports—many more than the 64% who turned down the airline’s contract proposal last month. If they do, it would be the first strike by flight attendants in Southwest’s history.

“98% YES sends a strong message of solidarity,” the union wrote on X. “We will do whatever it takes to get a Contract that recognizes our contributions to the success of our co.”

As a first step in their protest, many Southwest flight attendants will join thousands of airline workers on the picket lines for the worldwide Flight Attendant Day of Action on Feb. 13. Organized by the Association of Professional Flight Attendants, it will include picketing at more than 30 airports globally.

The flight attendants cited cost of living increases as well as a better deal offered to pilots, whose new contract includes a 50% pay raise over the next five years.