Striking British Midland staff were prevented from marching through Dublin Airport's departure terminal this afternoon.
Extra gardai and airport police were drafted in to stop the 130 protesting workers from entering the departures area.
There was no confrontation and the march instead moved on to the Aer Rianta office where the workers handed in a letter of protest.
They have accused Aer Rianta of frustrating their strike, which is over plans by British Midland to transfer their ground handling operations here to another London-based company.
A ballot of the ATGWU members taking part in the strike will be held this evening, with members being urged to vote for secondary picketing on all Aer Rianta offices within seven days.