Leaders of British Airways cabin crew will reveal their next move today in the long-running dispute over cost-cutting which threatens disruption to flights later this month.
Unite will hold a news conference at its London headquarters following the breakdown of talks aimed at resolving the bitter dispute.
The union will have to give seven days notice of a strike, although it has ruled out taking action over Easter.
BA's chief executive Willie Walsh has made it clear he is not prepared to see the union "ground" the airline, and he has drawn up contingency plans to deal with strikes.
Around 1,000 volunteer staff have been trained to cover for cabin crew in the event of a strike.
Meanwhile, Unite said it will be meeting with BA over a second dispute involving thousands of BA ground services staff, including baggage handlers, over new contracts.
Unite said it will hold a consultative ballot and if union members voted in favour, there would then be an industrial action ballot, although this is weeks away.
The union said talks had been taking place for around a year about changes BA wanted to make, claiming that the airline had recently written directly to staff with details of new contracts.
Steve Turner, Unite national officer for civil aviation, said: "It is hugely concerning that BA feel that management by imposition is their preferred approach.
"Very soon, no worker at the airline will feel that either their job or their terms and conditions are safe. This instability cannot be healthy for the airline."
A BA spokesman said: "We are consulting with our ground handling staff at Heathrow about potential changes to improve the way in which we work.
"Any talk of a ballot for industrial action is speculative and premature."