Construction union Ucatt has sent a dossier to the government exposing the illegal treatment of agency workers on sites run by some of the industry’s biggest contractors.

The document, seen by Building, was submitted to the Department for Business Enterprise and Regulatory Reform (BERR) at the Vulnerable Worker Enforcement Forum on 19 September as part of a campaign to extend legislation for gangmasters to the construction industry. It lists 16 contractors that it claims are using such workers.

Details of the document emerged as a debate on the matter was held at the Labour conference between union leaders and John Hutton, the business secretary.

Grievances listed in the document included lack of holiday or sick pay, late payment of wages, breaches of working time regulations, and agency workers being paid less than permanent workers.

Ucatt said breaches were affecting many agency workers in the construction sector, and “very often migrants”.

Hutton applauded the unions for their role in the vulnerable workers forum, but remained firm on his stance not to review the gangmasters legislation.

He said: “It’s not progressive or family friendly if new rules make firms think twice about taking on extra workers, or at worst, put people out of work.”

The Gangmasters Act covers workers in the agriculture and shellfish-gathering sectors.