The Finnish Construction Trade Union on Tuesday issued a strike notice covering the nuclear power station construction site in Olkiluoto.
The union said in a statement that temporary employment agency Rimec, thought to be registered in Cyprus, had withheld more than third of the pay of its Polish builders for tax and social security contributions but failed to explain where the money had been rendered.
It added that talks with Rimec and French builder Bouygues, the main contractor in Olkiluoto, had been fruitless and that all work at the site would stop on 10 September if no agreement was reached by that date.