Primary school teachers are to engage in rolling industrial action from September.
In a unanimous vote, delegates to the INTO's annual conference supported action, which they say will not directly impact on teaching and learning.
In another emergency motion, they deplored the abolition of special classes for children with learning disabilities.
One speaker said the abolition of these special education classes will cause serious damage to children and save just €17 per day per pupil.
The INTO already has a mandate for up to two days action over the Government's handling of the economy.
Now it is to engage in forms of non-cooperation in protest at education cuts, members say it will not impact on teaching and learning.
In a historic development, the union today elected its first ever female General Secretary.
Sheila Nunan will replace John Carr when he retires next year.
Emergency motions relating to cuts in teachers pay and conditions were debated by all three teachers' conferences.
Minister O'Keeffe got a decidedly frosty reception from the Teachers' Union of Ireland in Cork this afternoon.
A number of delegates shouted 'shame' and 'lies' as the Minister started speaking and more than a dozen walked out.
Others held up placards condemning Government cutbacks in education.
During his speech he was heckled and jeered a number of times and during the part of his speech when he said the cutbacks were being imposed in a fair and equitable a manner as possible he was completely drowned out by angry delegates.
TUI President Don Ryan received five standing ovations in the first few minutes of his speech, which attacked the Government cutbacks.
Mr O'Keeffe's welcome from the Irish National Teachers' Organisation delegates in Letterkenny yesterday was also hostile.
He later got a similar reception from the Association of Secondary Teachers in Ireland members.
At the ASTI conference in Killarney, huge anger among delegates has forced the suspension of a vote on a motion in protest at the increase in the public service pension levy.
There has been strong condemnation by some delegates of the role played by the union itself and by the ICTU in allowing the levy to be imposed in the first place.
After several hours of debate, it was proposed that a new emergency motion would be put forward tomorrow morning.
It is understood that this new motion will advocate industrial action.
Delegates at the INTO Congress have also called for an end to the use of pre-fabs for classrooms.
