British Airways staff will walk out on strike over the festive period for nine days.
Cargo workers at Heathrow are to take nine days of strike action starting on Christmas Day in a row over pay and conditions.
Unite said its 840 members face pay cuts and changes to their terms and conditions.
Strike action will begin on December 25 and end on January 2.
Unite assistant general secretary Howard Beckett said: “Unite has bent over backwards to give British Airways the opportunity to make a fair offer to its cargo workers and it has failed to do so.
“As a consequence Unite has no option but to announce strike action.”
