The secondary teachers union, the ASTI, will enter formal talks with the Department of Education today in a bid to resolve its dispute over the Haddington Road Agreement.
It is the only teacher's union to reject the public service pay deal and has undertaken a campaign of industrial action in protest against it.
ASTI members are refusing to take part in out-of-hours duties, such as parent teacher meetings, and are not participating in training for the the new Junior Cert cycle.
The Education Minister Ruairi Quinn is adamant that the Haddington Road Agreement is not up for re-negotiation.
Today's talks are likely to focus on a number of contentious issues, including payment for supervision duties, something ASTI members continue to receive while teachers from other unions do not.