BA cabin crew union Unite today (March 29) said it planned to raise £700,000 to back its battle with the airline.
The money will come from a compulsory 2% levy on its branches for the next quarter.
The fund will be in addition to the money the union is already paying its striking cabin crew members.
The plan was approved by the union’s executive earlier today.
The latest move comes as cabin crew at the airline are set to strike for a fourth day tomorrow (March 30).
They are due to resume normal working on Wednesday.
It is the second strike the union has called this month.
Tony Woodley, Unite’s joint general secretary, said: "This is an unprecedented move and it shows that Unite is absolutely determined to give our members all the support they deserve in winning this battle against the BA bullies.
"We continue to search for a decent settlement in this dispute but cabin crew are not going to be driven back to work for lack of resources."
The dispute between BA and Unite is over changes in working conditions for cabin crew.
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