British Airways flight attendants voted to take industrial action over the Christmas and New Year travel season, threatening what would be the carrier’s first major walkout in six years.

More than 2,500 of BA’s 16,000 cabin crew will strike some time after Dec. 21 if a raise better than the two percent currently on offer isn’t forthcoming, the Unite union said Wednesday. The employees are qualified to work on a range of aircraft, so that a walkout would impact both short- and long-haul routes.

“BA pay rates are indefensible and the crew are at breaking point,” Unite official Matt Smith said in a statement, adding that a significant number of members have had to take second jobs and that many go to work unfit to fly because they can’t afford to take time off.

Shares of British Airways parent IAG SA fell as much as 2.3 percent and were trading 2.1 percent lower at 436.90 pence as of 3:48 p.m. in London.

British Airways hasn’t suffered a single strike since the last action by cabin crew in 2010, according to a spokeswoman. That dispute, which saw 22 days of walkouts in a year, ended in defeat for unions in 2011 after workers accepted a deal that included drastic salary cuts for new recruits.

IAG’s closest competitors Air France-KLM Group and Deutsche Lufthansa AG have suffered numerous walkouts in recent years as they’ve sought to cut costs and restructure in order to combat a squeeze from discount carriers in Europe and Persian Gulf operators on long-haul routes.

Salaries for new British Airways “mixed fleet” cabin crew have been advertised as being worth between 21,000 pounds and 25,000 pounds ($27,000-$32,000) a year, but in practice begin at 12,000 pounds plus an additional 3 pounds for each hour flying, according to Unite.

BA said it has proposed “a fair and reasonable pay increase” worth seven percent over three years, in line with pay at rival carriers. Because Unite members among mixed-fleet crews account for only about 15 percent of the total the impact of any walkout will be limited, it said. Other crew groups participated in the last strike, increasing its scope.

This article was written by Benjamin Katz from Bloomberg and was legally licensed through the NewsCred publisher network.

Photo Credit: British Airways' cabin crew could strike for the first time in six years next week. Pictured are flight attendants in 2014. British Airways