Dozens of the UK's biggest retail chains have taken on unpaid job-seekers, as part of a government-sponsored "work experience scheme".

The arrangement, aimed at unemployed 16- to 24-year-olds, is designed to give job-seekers valuable work experience, with the ultimate aim of getting them off welfare and into employment. The reality is that young people are forced to work for free in order to receive their full benefits, emerging weeks later with almost unchanged job prospects.

Thousands of jobs are being filled by these unpaid job-seekers. Not only is the scheme said to be reducing the amount of paid work available, but in practice it is subsidising big companies to take on unpaid workers. The effect: these big chains get millions of pounds worth of labour, free of charge.

Last November, the UK chancellor, George Osborne, announced that the number of eight-week work experience placements would be increased to 250,000 over three years, to be funded from the nearly £1bn "Youth Contract".

At least one worker who has emerged from the programme is intending to challenge the British government, on the grounds that the work is "forced labour", in contravention of European law.