* Long-running dispute has cost BA 150 million pounds
* Union to hold consultative ballot as soon as possible
* PM Cameron calls for end to dispute
(Adds BA statement)
By Tim Castle
LONDON, Oct 20 (Reuters) - The union representing cabin crew at British Airways said on Wednesday it would ballot them on an offer to settle a year-long dispute that has brought strikes costing the airline 150 million pounds ($235 million).
Tony Woodley, joint General Secretary of the Unite union, said he had met cabin crew representatives on Tuesday and they had agreed to put the offer to a ballot of members as soon as possible.
"Representatives agreed that it is the best that can be achieved through negotiation in the current climate," Woodley said. "Our members ... will now decide whether this offer meets their requirements."
BA said it thought the offer, the details of which have not been made public, was fair.
"The offer we have made, based on our previous proposals, is very fair and reasonable and represents a genuine solution to the remaining issues in this dispute," a BA spokesman said.
A key sticking point in resolving the dispute, which originally centred on cuts to pay and staffing levels, has been the airline's decision to remove staff travel perks for cabin crew who took part in the strikes.
However, the head of Unite's cabin crew branch BASSA told members in an email that BA had made enough changes to an earlier offer to warrant a ballot to see if it was acceptable.
"It is now up to you. If you vote against the offer, the dispute goes on. If you vote to accept, the dispute is over," BASSA Secretary Duncan Holley said.
Prime Minister David Cameron called for an end to the dispute.
"I think the most important thing is this strike ends, this action ends, and that British Airways gets back to working properly," he told parliament.
"There's a hugely competitive airline sector out there, and those of us who love our national carrier and want it to be a success, want to see people go back to work and work out how to make it compete with others," he said.
($1=.6360 pounds) (Reporting by Tim Castle, Adrian Croft, Kylie MacLellan and Rhys Jones; Editing by Will Waterman)