British Airways could be facing a fresh threat of strikes in its long-running row with cabin crew when the result of a fresh ballot is announced.
Thousands of members of Unite have been voting on the latest offer aimed at ending their bitter dispute over pay, jobs and conditions, with a "strong recommendation" to reject.
Cabin crew staged a series of strikes last month which caused travel chaos for thousands of passengers and cost the airline tens of millions of pounds.
Tony Woodley, joint leader of Unite, said in a letter to the cabin crew that BA was treating staff like second-class citizens, "branded" for going on strike.
Mr Woodley said the reasons the union was urging rejection were the failure of BA to restore travel concessions taken away from those who went on strike, and disciplinary action against more than 50 union members.
"The charges in the great majority of cases are entirely trivial and barely worthy of a slap on the wrist, let alone the sack.
"This evidence of victimisation and draconian punishments - in some cases directed against your representatives - render worthless the words in the offer designed to rule out such behaviour."
Mr Woodley added that Unite had lost trust in BA's commitment in finding a solution to the dispute, saying: "Any agreement is only as good as the integrity and sincerity of those putting their names to it. By their actions and behaviour throughout the dispute, and continuing to this day, it is impossible to take BA management's words at their face value.
"I have had a considerable experience of strikes and disputes. Normally, the sort of issues we are referring to here - the removal of sanctions imposed during a strike, the speedy and sensitive winding-down of all but the most genuinely serious disciplinary issues arising from a dispute - are straightforward matters of industrial common sense, dealt with swiftly once the issues of substance between the two sides have been resolved.
"Yet in this case it is precisely on these issues that management has proved most intransigent of all."