The Teachers' Union of Ireland has passed a motion instructing the union executive not to enter any further Croke Park II talks with the Government or the management side.
At the TUI conference in Galway, delegates also instructed the executive committee to reject any imposition of the Croke Park II proposals on members by the Government or the Irish Congress of Trade Unions.
The motion directs the TUI executive to immediately ballot for a withdrawal from membership of ICTU if the proposals are imposed on the members.
It also instructs the executive to work with other unions opposed to Croke Park II to prevent its implementation.
During an hour-long debate, delegates voiced frustration and anger at the proposals.
The proposals would see teachers working extra hours, losing allowances, including supervision and substitution payments, and experiencing pay cuts in higher grades.
The TUI is the first union to return a ballot result on the proposed public service agreement, as 86% of members overwhelmingly rejected it.
TUI President Gerry Craughwell has claimed there were no real negotiations involved in reaching the new proposals.
He said that real negotiation does not take place when one of the parties can inflict its will on the other because it has a finger on what he called "the nuclear button".
Mr Craughwell told delegates that during the overnight sessions, trade union representatives had sat around chatting amongst themselves as they waited for what he called "unilateral announcements".
Earlier, the TUI general secretary warned that teachers may withdraw from activities previously carried out on a goodwill basis out of frustration at the demands of the new proposals.
John MacGabhann accused the Department of Public Expenditure and Reform of treating public servants as if they are the enemy rather than the bulwark of the State.
He said the department had been given what he called extravagant and excessive powers to regulate public services, and he described this as perverse.
Croke Park II a 'betrayal' - ASTI president
Minister for Education Ruairi Quinn was heckled by a small group of protestors as he arrived at the ASTI convention in Wexford.
Around ten people later walked out during his speech.
Mr Quinn told delegates he would shortly be bringing draft legislation to Government on the issue of school enrolment policies, which would attempt to make school applications more transparent and fairer.
He also said there were no plans to change Transition Year in secondary schools.
The association’s president told delegates that at least half of second-level teachers under 30 years old were on contracts of just one year or less.
Gerry Breslin said the Government, by pursuing a second Croke Park agreement, was in breach of the first and called it a betrayal of members.
He said to ask teachers to work an extra 49 hours annually was an insult to them.
He also asked if it is right to seek to cut the pay of teachers while the Government refused to increase taxes on those earning more than €100,000.
Addressing Minister Quinn, Mr Breslin said the State had been complicit in enabling multinational companies to avoid their responsibility to contribute fair and responsible taxes.
He also outlined what he called members' grave concerns over plans to reform the Junior Cert and said teachers wanted to be consulted.
Quinn heckled at INTO conference
Minister Quinn was also repeatedly heckled during his address to primary school teachers at their conference in Cork.
Delegates at Irish National Teachers' Organisation conference held up red cards at the minister.
INTO President Anne Fay was forced to intervene to call for attention for Mr Quinn during his speech.
Incoming INTO President Brendan O'Sullivan said that it was clear from the minister's address to the conference that he is "totally out of touch" with teachers' concerns about the Croke Park proposals.
Speaking on RTÉ's Today with Miles Dungan, Mr O'Sullivan said that teachers are very angry.
He warned against interpreting the union executive's decision not to recommend either acceptance or rejection of the proposals as tactic approval.
The minister said he respects that public sector unions have to make their own decisions on the proposals.
Mr Quinn will also speak at the Association of Secondary Teachers in Ireland conference in Wexford this afternoon.
Both the INTO and the ASTI are currently balloting on the proposals.
Teachers have been angered by the Croke Park proposals, which include additional unpaid hours, increment freezes and pay cuts for some higher grades.
Warning of disruption to third level exams
Students in Institutes of Technology face the possibility of disruption to examinations after the TUI threatened to withdraw from setting and marking exams.
The move is in opposition to the Croke Park proposals, which involve the elimination of additional payments for setting and correcting exam scripts totalling around €4m a year.
The TUI division representing third level lecturers passed a unanimous motion deploring the proposal to eliminate the payments.
In the event of the proposal being accepted by a majority vote of the Public Services Committee of ICTU, the motion instructs the TUI executive to ballot members on a directive banning the setting and marking of exam scripts.
The motion was proposed by the Dublin Colleges branch. Delegate Alice Prendergast said this was the first motion calling for actual industrial action.
She said the Government seemed to be allocating around 18 seconds to mark each script.
The TUI represents up to 4,000 lecturers in the Institutes of Technology.