The government has launched a crackdown on illegal migrant workers in construction, warning that employers could face unlimited fines.

The Home Office and the DTI are clamping down after a spate of reports claiming that foreign workers have been employed illegally. The departments have issued notices to industry bodies reminding them that they face fines of £5000 for each illegal worker. In some cases the companies could face unlimited fines.

The Construction Confederation is working with the DTI to produce appropriate guidance notes for employers. A confederation spokesperson said: “We are working with the government to remind employers of the checks that need to be made on workers, and inform them of the penalties for not doing so.”

News of the crackdown comes as the European services directive on migrant workers, known as the Bolkestein directive, has been delayed for three months because of wrangling in the European parliament. Unions believe the decision to delay its introduction could lead to it being dropped. The directive would allow European workers to work in the UK under the terms and and conditions that exists in their country of origin.

The first vote on the draft directive will now take place under the anti-directive Austrian presidency, which unions say will make it harder to push through. Representatives of UK unions have met European counterparts to consolidate opposition to the legislation.