The union representing British Airways cabin crew said it was to ballot members on further industrial action that could disrupt summer travel, as the last of three five-day strikes neared its end.
"There will be another ballot and the outcome of that ballot will determine what we do," Unite's joint leader Derek Simpson told BBC radio on Wednesday. "It (the timing of the ballot) is a matter that is being discussed at the moment."
A new vote will take at least six weeks, making mid-July, when British schools start breaking up for summer, the earliest possible date for a new wave of stoppages.
BA cabin crew will end their latest five-day strike late on Wednesday. The long-running dispute has cost the airline around GBP£150 million (USD$217 million) so far. Last month, BA posted a record full-year loss of GBP£531 million.
The strikes stem from BA's decision last November to cut cabin crew pay and alter staffing levels on flights to save GBP£62.5 million a year in costs.
With the cost savings dispute largely resolved, the issue of travel allowances for cabin crew has become the main sticking point in the conflict.
Simpson said BA chief executive Willie Walsh had backed himself into a corner on the travel question and was "desperate not to settle".
Earlier this week, Walsh said he would hold out against the striking cabin crew "for as long it takes".
Conciliation service ACAS said it would set a date for peace talks to resume shortly.
The most recent strike followed a five-day stoppage last week and previous walkouts in May and March.
BA said it had operated 80 percent of long-haul and 60 percent of short-haul flights from London's Heathrow airport, with services from London City and Gatwick airports unaffected over the latest strike period.