The Teachers Union of Ireland (TUI) executive committee is to advise its members to reject the proposed new national partnership pay deal agreed last week.
The move could see the Government withholding pay rises of 10 per cent over 27 months to the union's 13,000 members.
The president of the second- and third-level teachers' union, Paddy Healy, is also hoping that other public-service unions might consider joining with it in looking for the new deal, entitled Towards 2016, to be renegotiated.
Under the terms of the proposed deal, the TUI believes its members will be forced to introduce recent education legislation relating to issues such as special-needs provision and disadvantage.
However, it claims the deal contains no guarantees of additional resources to implement these changes, and that the pay increases it envisages are "barely above inflation".
"TUI is opposed to changes in conditions of service and increased workload being imposed on members in return for national pay rounds which principally compensate for inflation," Mr Healy said yesterday.
The union retains the right to pull out of the new partnership deal altogether if the decision of its executive is supported at a special TUI congress this month, and ratified by a subsequent nationwide ballot of members.
However, like other unions, it has in the past voted to reject previous pay deals but agreed to abide by the overall decision of Ictu's members to ratify and implement the deals.
The position of the State's largest trade union, Siptu, is also widely viewed as critical in deciding whether the deal will be ratified at a special Ictu congress on September 5th. It has traditionally supported pay deals.
As a result, it is seen as extremely unlikely that the TUI executive's decision will threaten the ratification of the overall pay deal by Ictu's members.
The central executive of the State's largest second-level teachers' union, the ASTI, is preparing to discuss the issue this weekend. A weekend meeting of the executive of the primary teacher union, the Irish National Teachers' Organisation (INTO), voted to recommend the new deal "on balance".
Commenting on the TUI executive's decision, Minister for Education Mary Hanafin yesterday said she hoped the union's members would see the deal as a broad agreement which does not just address the issue of pay.
David Begg, Ictu general secretary and a governor of the Irish Times trust, said the union was "perfectly entitled" to reject the deal if "that is what it wants to do".
"It depends on the outcome of the Ictu congress in September whether it is accepted or rejected."