British Airways cabin crews plan to strike during the Christmas holiday and into the new year, which could disrupt the plans of tens of thousands of travelers between the U.S. and Britain.

Unite, the union representing the crews, announced Monday that its members voted to strike from Dec. 22 to Jan. 2, the airline said. A strike could lead to cancellations on all the airline's routes.

"A strike is senseless and we urge Unite to draw back," Willie Walsh, British Airways CEO, said in a statement. "It is very sad that they are seeking to use the Christmas holiday plans and family reunions of hundreds of thousands of people to try to pursue their case."

With up to 540 flights a day in and out of London's Heathrow Airport and roughly 80,000 passengers traveling on peak days, British Airways is reorganizing flight schedules and trying to reassure travelers they'll be accommodated.

British Airways has about 40 flights a day between the U.S. and Britain, ferrying roughly 10,000 fliers.

Passengers booked to fly during the 12-day strike, or the 48 hours before or after, can change their trip to another date in the next 12 months at no additional cost, the airline says.

If the airline cancels a flight because of the strike, affected passengers can get a refund, make a reservation on another or re-route their trips. British Airways says it plans to notify customers about changes to their flights by e-mail or text.

The strike stems from the airline's decision to cut the number of cabin crewmembers on long-haul trips from 15 to 14, as well as concerns about wages. It was approved by more than 92% of union members who cast a ballot and will be the first strike by the airline's cabin crews in 12 years.

"You don't often get ballot results like this unless there is a deep-rooted sense of anxiety, concern and anger," said Len McCluskey, Unite's assistant general secretary.

British Airways lost $346 million from April 1 through September. And the airline says it's had to cut costs to operate during a time big-spending business fliers and leisure passengers are cutting back on travel during the recession.

A court is set to rule in February on the change in the number of cabin crewmembers, which union representatives says was not negotiated.

Bob Harrell, a consultant to the airline and travel industry, says that British Airways has been especially hard hit, as business travelers from the financial services industry who pay top dollar flying back and forth between London and New York have been grounded since last year's financial meltdown.

"Having a strike at any company is the worst possible outcome of labor negotiations, but sometimes it happens," he says. "It's all about money and power with labor. And this is a demonstration of their power."