Union insiders warn that the dispute with British Airways is likely to be “drawn out and bitter” as cabin crew prepare to vote on strike dates.

The potential fight comes following this morning’s announcement made by Len McCluskey, Unite’s assistant general secretary and lead negotiator with BA, of seven proposed dates for strikes before the end of this month on which Unite members will be balloted.

The strikes could be averted only if Unite’s BA cabin crew members vote to accept a new offer from BA, an offer the union has already recommended against. The result should be known by next week.

However, battlelines are already being drawn. One union insider claimed it was unlikely that the BA deal would be accepted. He added: “This will be a very long, drawn-out, bitter dispute. We are under no illusions about the depths to which British Airways will lower themselves.”

The comment reflects the anger felt by the union following BA’s turning down of an offer put forward by Unite which it claimed would save the airline £62.5 million, a similar figure to the amount BA said its own changes to cabin crew working conditions and pay would save.