Labour leader Pat Rabbitte said yesterday there was "immense potential" for large-scale exploitation of Romanian and Bulgarian workers by "unscrupulous employers" next year.
He said that despite Government plans to introduce work permits for citizens of the two new EU accession states there would be no restriction on people from both countries who wished to travel to Ireland, nor on those who came here to work on a self-employed basis.
He added that there is "a huge problem of false self-employment in the construction sector in particular" and a demand for "ever cheaper labour from bogus sub-contractors".
Ireland faced the prospect of having Romanians and Bulgarians "working in the black economy, afraid to put their heads up or to join a union".
Addressing 350 delegates at a Siptu regional conference in Waterford last night, Mr Rabbitte described Ireland as a country with "a strong economy but a weak society" and called for a major expansion in the inspection of workplaces to enforce good workplace standards.
Siptu south east and midlands regional secretary Mike Jennings told the conference that "migrant workers continue to be treated like units of labour instead of people". He said many were exploited in "dirty, difficult and sometimes dangerous jobs at scandalously low wages" by "free marketeers and exploiters".
Referring to the mushroom industry, Mr Jennings said that "pay levels and working conditions are so appalling that only the availability of desperate and vulnerable people from Latvia and other EU countries keep up employee numbers".
This afternoon delegates will be addressed by Janusz Sniadek, president of Solidarnosc, the largest trade union in Poland, which has established a project with Siptu to inform Polish workers of their rights.