Taoiseach Enda Kenny insists that legislation on pay cuts going through the Dail and Seanad next week will be used against unions that don't sign up to the Haddington Road Agreement.
The Taoiseach's comments came in the wake of decisions by two second-level teacher unions, the Association of Secondary Teachers Ireland (ASTI) and the Teachers Union of Ireland (TUI) not to put the proposals out to a ballot of members because they were not sufficiently improved.
Both unions say that they will respond with industrial action, up to and including strike, from September if cuts go ahead.
As the controversy over their decisions continued, it emerged that the ASTI rules stipulate that its standing committee, which took the decision not to ballot members, does not have authority to accept or reject a final offer in respect of incremental salary.
However, last night the ASTI and TUI said that they did not regard the proposals as a "final offer" and they would consult with their members when there was "sufficient improvement and clarification".
The two unions said they believed it was "still possible to conclude an agreement and we note that this is provided for in the Bill published by the Government".
The Irish Federation of University Teachers (IFUT) has said it will ballot its members, but a decision on whether to issue a recommendation will await a special conference on June 8.
IFUT will be seeking legal opinion on the legal and constitutional validity of the proposed government legislation aimed at imposing its proposals.
The Irish Medical Organisation (IMO) has postponed for two weeks a decision on the proposals amid concerns over cuts to hospital consultants' pay.
They are seeking further clarification on the terms of reference for talks which are due to start in June on how the health service can persuade more medical graduates to stay and work in hospitals here.
Already the country's biggest trade unions, SIPTU and IMPACT, along with the Irish National Teachers Organisation (INTO) have recommended acceptance of the deal.
As the fall-out from Haddington Road continued yesterday, Mr Kenny said those unions which signed up will have their agreements honoured, and "those unions that do not will be subject to legislation which will go through the Dail and the Seanad next week".
He said the Government had made it "perfectly clear. We have to achieve savings of €300m this year rising to a billion by 2015. Everybody knows that, our country is in a very difficult time".
Finance Minister Michael Noonan held out no hope of any more talks: "This is the final round of negotiations."
Education Minister Ruairi Quinn was at one with his Cabinet colleagues.
He said it was the unions' right to choose "but we have to regain our economic sovereignty. This decision, painful for everybody, is part and parcel of that".
Mr Quinn said he did not "honestly know" when teachers' pay packets might be cut but said they would come into effect as soon as it is practically possible to so do" after the legislation was passed.