British Telecom faces the threat of industrial action as its annual report, published later, is expected to show increased bonuses for top staff.
The Communication Workers Union will discuss balloting its 60,000 members at BT after rejecting a 2 per cent pay offer.
An emergency motion to the union's annual conference in Bournemouth warns of an industrial action ballot after BT "closed the door" on further pay negotiations.
Delegates will debate the prospect of action just hours after BT publishes its annual report, which is widely expected to show increased bonuses for staff including chief executive Ian Livingston.
He is expected to pocket £1.6 million - that is twice his annual salary of £800,000.
The group recently announced £1 billion in profits for the year to the end of March, which came as a marked improvement on the £134 million loss a year earlier.