"Many of them are packing food for supermarkets,” said Labour mp for West Renfrewshire, Jim Sheridan, "and despite some gangmaster activity already legalised, further legislation is essential to end exploitation and prevent more tragedies like Morecambe Bay".

It was reported that tens of thousands of migrant workers are employed by 3,000 gangmasters across the UK. The case of seven South African workers was used at the conference to highlight the scandalous employment conditions, with one worker having shown his pay packet as proof of only receiving 78p for a week's work after expenses.

Don Pollard, an official from Transport and General Workers' Union (TGWU) has been campaigning since 1995 to end migrant worker exploitation and has recorded many instances of abuse. In the case of the seven workers from South Africa, they were lent the funds to travel to Britain, to be repaid at 100 per cent interest, were paid £4 an hour to pack fruit for sale in UK supermarkets, lived in cramped conditions in a house with 24 other workers, and were required to pay the gangmaster the weekly costs of £55 for rent and £17.50 for administration and transport.

A coalition of MPs, unions, retailers and farmers has joined forces with the TGWU to rally the government's support for a private members' bill, enforcing gangmaster licensing. Jack Dromey, deputy general secretary of the TGWU, said: "The weaknesses of the law are undermining reputable labour providers and responsible retailers by allowing the exploitation of vulnerable legal workers."

Dromey called on MPs to vote on 27 February in order to guarantee that the proposed law is passed. "The bill will ensure that gangmasters obtain a license and operate transparently to establish a paper trail that has been missing. We have a remarkable coalition to end this modern day slavery- MPs must be there."