British Airways said on Friday it was "appalled" by trade union Unite's decision to call a strike involving one of its five cabin crew fleets on Christmas Day and Boxing Day (Dec. 26).
Unite said in a statement earlier on Wednesday that thousands of British Airways cabin crew had voted in favour of strike action in a pay dispute.
In a statement, the airline said Unite's "calculated and heartless action is completely unnecessary" and that it would plan to ensure that all customers could travel "so that their Christmas arrangements are not ruined".
Unite was not immediately available for comment.
Between 2009 and 2011, BA suffered two years of bitter industrial action as it tried to cut 1,700 cabin crew jobs and freeze pay.
(Reporting by Bhanu Pratap in Bengaluru; Editing by Catherine Evans)