Education Minister Ruairi Quinn has been accused of being out of touch as he was heckled and faced a red card protest at a teachers' conference.
About 100 members of the Irish National Teachers' Organisation (Into) repeatedly interrupted his address and held aloft messages attacking Government policy.
Mr Quinn told delegates at the primary teachers' meeting that he understands the difficulties that the new Croke Park deal creates for public sector workers.
"I am acutely aware that these proposals are very challenging for your members," he said. "While I respect the fact that your ballot is currently under way, you will understand that I have a responsibility as a member of this Government to commend the proposals to you."
Incoming president of the Into union Brendan O'Sullivan claimed Mr Quinn was out of touch.
"He told us that he was aware that the Croke Park deal was challenging - well, that does not come near to describing the feeling," Mr O'Sullivan told RTE.
Mr Quinn is addressing the Into conference and also the Association of Secondary Teachers in Ireland. The Teachers' Union of Ireland last week overwhelmingly voted against the Croke Park deal. The Into ballot is ongoing while Asti has urged its members to vote against it.
Into general secretary Sheila Nunan later told delegates and the minister that a world class economy and a fairer, more equal society can only be built with a top-class education.
She said teachers are looking at a system that is crashing about them, devastated by the wrecking ball of austerity over the last five years.
Ms Nunan criticised class sizes, which she said were the second highest in Europe, and the shameful paring back of resources for children with special needs. She also accused Government of failing to offer newly qualified teachers anything but unemployment and emigration.