Staff at Dublin Airport are at "breaking point" and should not be blamed for delays, a union has said.
More than 1,000 passengers missed their flights from the airport due to queues on Sunday.
The airport has been asked to report back to the Irish government by Tuesday with solutions to the recent queue chaos.
About 190,000 departures are expected this bank holiday weekend, according to the Dublin Airport Authority (DAA).
The DAA has apologised for the weekend issues and said customers would not be left "out of pocket".