Up to 1,000 schools will face administrative disruption from Friday as school secretaries begin a campaign of industrial action over pay and conditions.

The staff represented by Fórsa say they have been victims of an "antiquated and discriminatory" two-tier pay system since 1978.

The union says that some secretaries employed by school management boards can earn as little as €12,500 a year, and only have non-permanent contracts, leaving them obliged to sign-on over the summer when schools are closed.

In contrast, another group of school secretaries directly employed by the Department of Education enjoy public servant status, along with higher pay rates, permanent contracts and pension entitlements.

A meeting this morning with the Department of Education ended without agreement.

The industrial action will begin with a one-hour work stoppage on Friday morning, along with protests outside at least 250 schools.

However, the school secretaries will also start a work-to-rule, under which they will refuse to engage with any public service administrative systems and databases.

They argue that if they are not paid or recognised as public servants, they will not carry out public service functions.

Fórsa estimates that the work-to-rule will cause significant disruption to administrative functions, without affecting students or parents.

It calculates that there are up to 3,500 school secretaries around the country and that Fórsa represents around a third of them.

Fórsa Head of Education Andy Pike said the Department of Education had failed to offer any credible proposals to end what he called the pay injustice facing most of the country's school secretaries.

He said the two-tier system had been in force for over four decades, but that in that time it had seen very little, if any, serious engagement with the department, whose position was to "constantly stall and disengage".

The Department of Education described the planned industrial action as "premature and unwarranted".

It urged Fórsa to reconsider the stoppage and work-to-rule, adding that it remains fully open to having further dialogue once the accurate cost of the claim had been calculated.

A spokesperson for the Department of Education said officials had met Fórsa representatives in late May, when the union had formally tabled a claim seeking public service pay scales, year-round working patterns and access to a public service pension scheme for secretaries and caretakers employed directly by schools, and whose salaries are funded from grants.

He said these demands were tabled as a follow-on claim a 2016-2019 pay agreement, which provided for a 10% pay increase over that period, and a higher minimum hourly rate of €13.

He noted that that deal does not expire until December.

He stressed that the Department must establish the full current cost of Fórsa's claim, and because it is not the direct employer of these workers, it is carrying out a survey to gain accurate up-to-date information on their pay and working hours.

The spokesperson confirmed that the Department had told the union that their claim will be fully considered once the current costings have been established from the survey.

It's understood the purpose of the meeting was to further explore the details of the Fórsa pay claim, as well as the nature of the planned industrial action.