The cost of the strike by British Airways cabin crew has cost the airline at least £140 million.

The estimate came from the Unite union as the dispute entered its 21st day today (Tuesday).

More than 40 per cent of BA’s operation has been hit by the strike despite the carrier’s contingency plans, according to union estimates yesterday.

Unite admitted that flights to important destinations from Heathrow, including New York JFK and San Francisco, continue to fly but claimed that passenger numbers were “severely down” and with some flights half empty.

BA has said that it is increasing the level of services operating as the dispute continues and that flights from Gatwick and London City Airport have been unaffected.