British Airways has posted a £164 million loss for the last quarter as the cabin crew strikes and volcanic ash cloud cost the flag carrier an estimated £250 million. It has also emerged that its cabin crew are plotting a 12-day strike over Christmas as their next weapon in the long-running dispute.

Millions of airline passengers could face severe disruption at the UK’s largest airports during the August bank holiday weekend after the trade union Unite announced a strike ballot of key BAA staff.

British Airways cabin crew have rejected the airline’s “final” pay offer, which raises the possibility of further industrial action. The union Unite, which represents 90 percent of BA’s 12,000 cabin crew, said 67 percent of its members voted against the revised offer.

The long-running dispute between British Airways and its cabin crew could finally be drawing to a close after the Unite union postponed a strike ballot due tomorrow, and put an offer from the airline to its cabin crew members. BA heralded the move as “a genuine opportunity” to end the row that had threaten to cause further disruption over the summer holidays.

Over 400 pilots at US carrier Spirit Airlines have gone on strike after failing to reach an agreement with management over pay and benefits. The five-day strike is due to end tomorrow and was called by the Air Line Pilots Association.

Nearly 400,000 people abandoned British Airways in May as strikes by cabin crew forced the airline to cancel hundreds of flights. Passenger numbers fell 14.2 percent to 2.3 million last month with economy revenues the worst hit.