Talks at the Labour Relations Commission to try to resolved the current dispute at Aer Lingus are continuing today.
Aer Lingus managment and pilots' representatives meet yesterday at the LRC, but no progress was reported.
The dispute could see hundreds of pilots at Aer Lingus being suspended without pay from early next week unless they agree to co-operate with moves to facilitate the opening of a new base in Belfast.
Already seven pilots have been suspended without pay. Up to 15,000 passengers daily could be affected if Aer Lingus flights are grounded as a result of the dispute.
Speaking today before entering the talks, LRC Chief executive Ciaran Mulvey said it would be "a long day but hopefully we can get some way towards resolving the dispute".
"We're all going to work together in a business like fashion," he added.
Assistant General Secretary of IMPACT, Michael Landers, said his union wants to see "a positive attitude" from the company at the talks.
"We want to see a serious addressing of the issues that we have with the Belfast base," Mr Landers said.
Aer Lingus said its position had not changed in relation to the Belfast hub and that the Tuesday deadline remained in place.