Aer Lingus pilots' dispute likely to hit Northern Ireland flights
Industrial action at Aer Lingus is expected to disrupt flights out of Belfast from Friday.
The airline is offering refunds to passengers of cancelled flights.
The industrial action is due to start tomorrow and the company said it did not know whether it will be in a position to operate its full schedule.
The pilots' trade union Impact announced the plans for industrial action over pay and rosters.
Impact said work-to-rule action at Belfast will start on Friday and could cause flight disruption.
Aer Lingus operates out of Belfast International Airport, flying to destinations such as Barcelona, Heathrow and Malaga but has said there are no planned changes to the Belfast routes.
Pilots based at Dublin, Cork and Shannon are due to take the same action from tomorrow.
A statement on the airline's website said: "We realise that this is extremely disruptive for our customers and we apologise most sincerely for the major inconvenience this may cause.
"We have activated our change for free facility for customers who have a booking to travel from Tuesday, June 7 up to Friday, June 10 inclusive.
"Customers who wish to change their booking to a later or earlier date of travel may do so, free of charge, by using this facility.
"Customers who wish to cancel their booking for travel on these days may also do so and will receive a full refund."
Talks between the airline and union chiefs broke down on Saturday. Michael Landers, of Impact, said that pilots at Belfast International Airport would not be available to work on their days off and would impose a one-hour delay on all flights.
"What Aer Lingus have said in relation to flights from Dublin is, if that action goes ahead they will cancel all flights for Tuesday and Wednesday," he said.
"Now, whether or not they propose to take similar action later in the week in Belfast I don't know."
Between 20 and 30 Aer Lingus pilots based in Belfast are members of Impact.
While the dispute in the Republic centres on rota arrangements, Mr Landers said the issues in Northern Ireland mainly related to pay.
He said: "Salaries in Belfast are lower. A lot of pilots have already left the base."