Unions leaders at Unite are threatening to hold more strike ballots for BA cabin crew which could disrupt the summer holidays.
Cabin crew at the UK national carrier were today (June 3) on strike for the final day of the current stoppage.
A third five-day strike is due to begin on Saturday, June 5.
Talks between the union and BA management broke down on Tuesday.
The union says its strikes are costing the airline £7m a day and have so far cost it more than £100m.
But BA, which last month reported a pre-tax loss of £531m for the financial year, has countered by claiming than more cabin crew are defying their union and reporting for work.
The airline said it planned to operate 80% of long haul and 60% of short haul flights out of Heathrow during the next planned stoppage.
Services at Gatwick and London City Airports are expected to operate normally.
The dispute is over planned changes in working practices for cabin crew.
But while this issue is said to have been solved, new sticking points are BA's refusal to re-instate travel perks for staff who have gone on strike or stop disciplinary action against others.
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