The government has failed to understand the urgent need to implement a gangmasters bill and is still ignorant of the scale of illegal activity, according to a damning report by MPs.
The cross-party environment, food and rural affairs committee called for measures to quantify the problem and money for research.
The 17 MPs, chaired by Conservative Michael Jack, were in favour of the gangmasters bill introduced by Labour's Jim Sheridan in January. The bill, which calls for licensing of gangmasters, was amended by the government to restrict coverage to agricultural work, the gathering of shellfish and the processing and packaging of such products. It has now reached the House of Lords.
The select committee recommended that the government transfer liability for illegal activity to retailers which did not take reasonable steps to ensure their suppliers used only licensed operators.
The dominance of major retailers in the supply chain meant that producers were pressured to work at high speed and low cost, which could encourage the use of cheaper illegal workers, said the committee.
However, the British Retail Consortium (BRC) insisted that it was up to government to police illegal gangmasters. "We do not believe that policy makers should shift enforcement of law from the relevant authorities and agencies on to business," said Kevin Hawkins, director general of the BRC. "There is no link between consumers receiving the freshest food at the lowest prices and the work of greedy criminals."