School secretaries will be taking part in industrial action today in a row over pay and conditions.
They will hold an hour-long work stoppage when schools open their gates this morning, followed by 'work to rule' action.
Their union Fórsa says they are taking the step as there was no breakthrough during talks with the Department of Education on Wednesday.
Demonstrations are expected at 250 schools across the country, while up to 1,000 schools could be impacted.
Fórsa has suggested today's action will cause "significant disruption" to administration work in schools but won't affect students or parents.
The union's head of education Andy Pike explained: "Nothing was tabled by officials from the department to end this long-standing pay injustice.
“In recent years, school secretaries have done everything short of industrial action in their campaign for pay equality."
He added: "They welcome the many pledges of solidarity they’ve received from politicians of all colours, but these are totally disconnected from the reality of the department’s position, which is to constantly stall and disengage."
The union says the dispute centres around a two-tier pay system - suggesting irregular and short-term contracts force some secretaries to sign on during school breaks.
The Government, meanwhile, says Fórsa's pay claim is a "follow-on claim from the current pay agreement" which runs until the end of the year, adding that the union's claim will be "fully considered" shortly.
Tánaiste Simon Coveney told the Dáil yesterday that any industrial action is "surely premature and unwarranted" as the current pay agreement is still in effect - but urged Fórsa to engage with the Department of Education "to try to find a way forward".