The union representing British Airways'
Unite, which represents about 90 percent of BA's 12,000 cabin crew, made the threat on the first day of a four-day strike, its second walkout this month.
We are not announcing any (new) strike action at the moment, and we do not have to until after April 8, a Unite spokesman told Reuters. It very much remains a possibility.
The dispute, like plans by railway staff to hold Britain's first national rail strike in 16 years in April, is embarrassing Prime Minister Gordon Brown, who faces an uphill battle to win a general election expected on May 6.
The ruling Labor party receives much of its funding from the unions, and the opposition Conservatives have accused Brown of weakness in his approach to the disputes because of this.
A general election is due by June and Brown is expected to call one for May 6. Labor has won three successive elections but is lagging the Conservatives in opinion polls, though the gap is narrowing and the result may be indecisive.
Labor has called for British Airways and Unite to resume talks.
It's very damaging for British Airways, its very damaging to the national economy, and it's very damaging to the very jobs of union members which the union exists to protect, Transport Secretary Andrew Adonis told Sky news.
That's why it is so important that they get back around the negotiating table and seek to resolve this dispute by talking and not by confrontation.
WANT TALKS, WON'T TALK
Both sides have said they are willing to talk, but no date has been set, and they continued their war of words on the impact of the strike.
BA said it hoped to fly more than 180,000 of the 240,000 passengers originally booked, and said 18 percent had rebooked with other carriers or changed the dates of their flights.
On Saturday, it said Gatwick and London City airports were operating as normal, and enough cabin crew reported for work at Heathrow to operate its published schedule of 70 percent of long-haul flights.
We have been able to minimize the impact but unfortunately, given that this is a very busy time of the year, we have not been able to provide alternative plans for all our customers, BA Chief Executive Willie Walsh said in a video posted on the airline's website.
Unite said support for the strike had been strong, 43 scheduled flights from Heathrow had been canceled, and passengers had been asked to disembark from six planes because of lack of crew.
BA says it wants to save 62.5 million pounds ($92.76 million) a year to help cope with falling demand, volatile fuel prices and greater competition.
The three-day stoppage last weekend cost the airline about 7 million pounds a day, BA said. Unite disagreed, saying the seven days of strike action would cost the airline nearly 100 million pounds.
Brown received some good news when Acas, the arbitration service, said Network Rail and the railway unions would resume talks on Monday in an attempt to settle a dispute over planned job cuts and changes to working practices.
(Additional reporting by Michael Holden; editing by Tim Pearce)