More than 360 Aer Lingus flights scheduled for the next two days have been cancelled as a result of the dispute between pilots and management at the airline.
Up to 40,000 passengers will be affected by the cancellations, announced by management for tomorrow and Friday in the wake of the pilots' decision to hold a one-day strike.
Aer Lingus public relations manager Ms Gráinne O'Malley said all passengers due to fly on Friday would receive a refund or, if possible, be rebooked on another carrier.
She noted, however, that "because it's a busy bank holiday, there is little chance of finding places for people".
The company will decide tomorrow whether Saturday's flights will go ahead as scheduled. Operations are being reviewed on a day-by-day basis, the airline said.
The decision to cancel all flights on Friday stemmed first from logistical problems emanating from tomorrow's strike and, second, from "the ongoing threat of further industrial action", said Ms O'Malley.
Passengers due to fly with the airline tomorrow had been rescheduled onto flights on Friday.
It was partly due to this "knock-on effect" that operations were ceasing, she said.
"We just won't be able to sustain operations because of the knock-on effect from Thursday and the ongoing threat of action."
However, the trade union IMPACT, which represents the striking pilots, described these reasons as "bogus".
It said that no strike action was planned for Friday.
Union official Mr Bernard Harbour added that the airline had managed to mount operations during previous disruptions and industrial actions over the past two years.
The company said today's flights would go ahead as scheduled, thereby facilitating a number of soccer fans planning to travel to Japan for the Republic of Ireland's first World Cup game on Saturday.
Ray Treacy Travel is to fly 400 soccer fans out of Dublin this evening rather than on Thursday as initially scheduled.
They are due to overnight in Amsterdam before starting the second leg of their journey tomorrow.
Only 21 Aer Lingus flights are to operate tomorrow between Irish, US and UK destinations. Crew and three aircrafts have been hired by the airline to operate the skeleton service.
A number of flights which are shared between Aer Lingus and other airlines are also to operate.
There is a possibility that other travellers will be affected by the industrial action if staff from other unions choose not to cross IMPACT picket lines tomorrow. Under industrial relations law, such actions are illegal.
However, they have occurred at Dublin Airport in the past.
Passengers due to travel with Aer Lingus in the coming days can contact one of the following numbers:
Callers in Ireland: 1800 222 221
Callers from the UK: 0845 08 444 44
Callers from the US: 1-800- IRISH-AIR
Or visit the company's website, www.aerlingus. com