Update - 5.45pm: A strike by Ryanair pilots will go ahead tomorrow as planned after management and unions failed to reach an agreement in talks today.
Both sides met for seven hours at Dublin airport today, but trade union Forsa offered little hope that enough progress could be made to call off the strike.
Almost 100 pilots based in Dublin will walk off the job at 1am.
30 flights between Irish and UK airports have been cancelled, with flights to European destinations escaping the cancellations.
Ryanair says 90% of those booked on the 30 cancelled flights have been re-accommodated or have applied for refunds.
Affected passengers have been contacted by email or text, and people whose flights have been cancelled are advised to visit the Commission for Aviation Regulationwebsite.
Earlier: Unions and management meet for talks to avert Ryanair pilots strike
Unions and management at Ryanair are set to meet today in an effort to break the deadlock over tomorrow's planned pilot strike.
The two sides will have talks at Dublin Airport around lunchtime.
However, Thursday's strike action by up to 100 pilots based in Dublin is set to go ahead.
The airline claims only flights to the UK will be affected and says passengers that have not been of informed of cancellations can assume their flight will go ahead.
Kenny Jacobs, the spokesperson for Ryanair, said: "What we've done is cancel flights on high-frequency routes to London and UK regional airports where we have got a lot of flights where customers can easily transfer to another flight."
The strike is being organised by members of the Irish Air Line Pilots' Association (IALPA), which is a branch of the Fórsa union.
The dispute centres on issues like union recognition, base transfers and seniority.
Ryanair has said the disruption is “unnecessary” and insisted it has already sent the FÓRSA union “written proposals on seniority, annual leave and base transfers.”
The Commission for Aviation Regulation has urged affected passengers to make themselves aware of their entitlements in the event the strike does go ahead.
Full details of passenger entitlements are available here.