SIPTU members at Aer Lingus and the DAA have voted overwhelmingly in favour of industrial action in a row over pensions.
Ballot results for IMPACT and other unions involved in the two companies are awaited.
However the ballot result is unlikely to affect travellers on the bank holiday weekend.
The strike ballot was held in protest at plans to reform the joint pension scheme known as the Irish aviation superannuation scheme.
The scheme currently has a deficit of around €700m but both Aer Lingus and the DAA have categorically ruled out injecting additional cash to deal with the shortfall.
Negotiations at the Labour Relations Commission have been adjourned for some weeks.