Talks between British Airways and unions have broken down, raising the threat the airline will be hit by more strike action over the summer.
An unofficial strike by BA employees over the weekend forced the airline to scrap hundreds of flights from Heathrow, the hub of its operations, which stranded thousands of travellers and took days to clear.
BA executives and union officials have been unable to resolve the dispute in the last two days, and a spokesman for the GMB union told Sky News the union would now ballot its members for industrial action.
Andrew Dodgshon, spokesman for the Transport & General Workers Union, today said the talks had broken down after 27 hours as BA had "dug its heels in" over its plan to introduce automated time recording (ATR) - the issue at the heart of the dispute.
Dodgshon said his union had not yet decided whether to ballot its members.
BA said the unions walked away from the talks after saying their opposition to ATR was their final position.
Europe's biggest airline said in a statement it offered to postpone the introduction of ATR until the two sides had negotiated the 2003 pay deal, but this was rejected.
As a result, it said it would introduce ATR at midday on Wednesday "when staff can use the new system for themselves and see that there is nothing to worry about".
The unions and BA said they were willing to reopen talks to discuss the dispute.
The sudden strike by about 250 BA ground staff at two terminals at London's Heathrow airport, the world's busiest international hub, from last Friday night disrupted the travel plans of more than 100,000 people over the weekend.
It also raised fears BA's drive to cut costs and rebuild profits was starting to fan workplace unrest.
The wildcat strike was prompted by BA's plan to introduce an automated "swipe card" system to record when employees begin and end their shifts. The airline says the system will improve efficiency, but workers are concerned it will lead to changes in shift patterns.
BA Chief Executive Rod Eddington yesterday warned that the failure of modernisation plans threatened the airline's future.
"The impact on our business (from the weekend strike) will be tens of millions of pounds, we're not sure what the exact sum is yet," Eddington told the BBC.
"But we also know that if we don't continue to modernise our business we won't be around in two years time."
BA has slashed more than 10,000 jobs to cope with the severe downturn in demand for long-distance air travel and to compete with the booming European no-frills airlines. It has had industrial disputes in the past as it has tried to change high-cost labour practices.
TGWU's Dodgshon said BA's restructuring, job cuts and cost-cutting in the last two years had all been achieved in cooperation with the unions - in contrast to its current stance.