Employers were accused yesterday by SIPTU of failing to pay the minimum wage or provide holiday entitlements to students employed for summer work.
The union's Cavan branch secretary, Mr Gerry McCormack, said that the number of students who had complained to SIPTU in recent weeks about the matter was "astonishing".
He said the problem was mainly in the services sector, such as bars, hotels, restaurants, shops, hairdressers and petrol stations.
Agricultural workers were also affected, he added.
