Unions representing airport security staff are warning of huge delays and cancelled flights at airports after lock-out notices were issued against their members.
E Tu and the Public Service Association said the Aviation Security Service's decision to lock out employees later this month was an irresponsible move which would inconvenience travellers.
Negotiations have broken down on pay talks between the parties, which have been going on for about a year.
The unions said it was unlikely that the Civil Aviation Authority would be able to provide full security coverage during the lock-out, which will take place between July 20 and 27.
"This is an extraordinary step and one that gravely concerns us," E tū National Organiser Kelvin Ellis says.