Workers gathered outside a branch of Tesco supermarket in Dublin last evening, to protest over the conditions of their employment.
The temporary agency workers claim they are paid less than contract staff for doing the same job and that they are pushed harder than is reasonable by management.
"It is very convenient for Tesco to use agency staff instead of giving us a contract," said Radek Sawicki. "We are cheap and Tesco takes no responsibility for our exploitation."
Two workers claim they were sacked from Tesco's distribution centre in Tallaght after they made a complaint to staff at the plant.
They argue that their productivity targets were pushed beyond reasonable levels.
A spokesman for Grafton Recruitment, through which one man was employed, denied he had been sacked or that he had been discriminated against.
"When he complained, we offered him a different job with exactly the same pay and conditions in the same area. There was no question of him being discriminated against or fired," said the spokesman.
A Siptu official said there was a substantial difference between the rates paid to agency temporary and contract workers, with agency workers earning around €357 per week while contract workers earn €540 for the same week's labour.
Although not involved in the protest, Siptu has complained to the Labour Relations Commission about Tesco's recruitment policy and it is thought that the case will be heard on August 12th.