LONDON, Feb 22 (Reuters) - The biggest union representing British Airways cabin crew said on Tuesday it is to re-ballot members over strike action after saying it feared a recent vote would be ruled as invalid.
Cabin crew voted last month to hold further strikes in a long-running dispute which has already cost the airline some 150 million pounds ($240 million).
However, BA argued that the ballot, the third held by staff backing industrial action, was unlawful. That led the Electoral Reform Society, the watchdog responsible for overseeing the vote, to qualify its official report, the union said.
"The new ballot follows moves last month by the airline to derail the vote conducted in December 2010 by the Electoral Reform Services, which saw 78 percent of Unite's crew members vote in favour of strike action by three to one," the union said in a statement.
Unite said the new balloting would take place between March 1 and March 28. (Reporting by Stefano Ambrogi; Editing by Greg Mahlich)