The new licensing system for gangmasters and agencies will leave thousands of temporary and migrant workers vulnerable to exploitation a union has claimed.

The TUC said the system would only be effective if all individuals and companies responsible for the supply of labour to the UK's agriculture and food processing industries are covered.

In its submission to the government's consultation on the proposed regulations for the licensing of gangmasters - due to come into force next year - the TUC said it is concerned ministers intend to limit the scheme to those agencies and individuals providing staff to work in abattoirs and fruit and vegetable picking and packing.

It claimed any move to limit the licensing scheme to the primary processing sector will open up a loophole ripe for exploitation by unscrupulous gangmasters.

The TUC would like to see all organisations providing manpower for secondary processing in the UK to also be covered by the new regulations.

Brendan Barber, TUC general secretary, said: “With instances of non-payment of the minimum wage and the confiscation of personal papers being reported by migrant workers, the government needs to get tough with unscrupulous suppliers of temporary labour.

“Law-abiding gangmasters have nothing to fear from a wide-ranging licensing system. It is only those currently operating illegally and on the fringes of the law who will have to clean up their acts.

“Ministers must allow the licensing scheme to have the widest possible reach. Only a scheme covering both primary and secondary processing will be robust enough to deter those ruthless individuals who are currently making a lot of money from exploiting large numbers of mainly foreign, temporary workers.”