Construction Workers from the SIPTU and BATU trade unions will hold a protest outside the Department of Education this morning.
Staff employed on projects within the Government's School Building Programme claim the Department has failed to uphold agreed industry terms and conditions.
They claim contractors are refusing to cooperate with trade union organisers who are seeking to ensure that workers are receiving the correct pay rates and conditions.
This will be the first in a series of demonstrations.
Pat McCabe, the SIPTU sector organiser, said the Education Minister Ruari Quinn is ignoring the key issues.
"The Minister- who we met in late 2012 - said he was concerned with the level of non-compliance with pay and conditions on the Department of Education projects.
"And he said that he wished the unions would be his eyes and ears, so to speak - however we are finding now that contractors are trying to obstruct us getting entry."
"We want the Minister to ensure we have access."
The demonstration is scheduled to begin at about 8am.