Of the 200,000 migrants entering the UK each year, 77,000 find work in the construction industry and around 10% of all construction workers are non-UK nationals.

While they plug a vital skills shortage, notably in London in the run-up to the London 2012 Olympics, there’s a dark side to migrant labour (see CM, April 2006).

Celebrated UK director Ken Loach’s latest film, It’s A Free World, released on DVD on October 1, focuses on the plight of those migrants at the bottom of the heap - the unskilled, non-English speakers – who are absorbed into a pool of casual day labourers, not knowing from day to day whether they will be working or not, and often bonded to their employer by debt.

The story centres around Angie, a strong-willed young English woman who sets up an illegal east London recruitment agency for these workers. Unfazed by the apparently minor Home Office punishments for running such operations, the money soon starts rolling in. But when one of her financial backers pulls out, she’s left with a lot of angry unpaid Eastern European workers.

The screenplay is based on real workers, says writer Paul Laverty: ‘Some had worked on one building, been tempted to another and another, and then never been paid. Others were abused on farms receiving a pittance - well below the minimum wage. A young Pole was actually cut in half with a rope reeling machine.’

According to Loach, the current employment system, which makes extensive use of recruitment agencies and outsourcing, and involves long sub-contracting chains, serves to obscure and encourage forced labour, trafficked labour and illegal migrants. He says it’s no coincidence that employers are only punished for not checking documents – if the government really wanted to tackle exploitation, they would be punished for employing workers in exploitative conditions.