File on 4 - Illegal workers

Lifting the lid on illegal London - welcome to a world of forged documents and faked identities. It's believed there are likely to be more than 200,000 illegal migrant workers in the UK's capital city. But how are they able to survive. How do they get work? In this special investigation, Jon Manel obtains rare access into the lives of some of London's illegal workers - lives often based on lies and deception. He discovers that some are now so much part of the system, they even pay tax and national insurance. He hears of miserable and difficult times spent living in the shadows. But other illegal workers say they are making a bigger contribution than many who were born here. "I'm doing a job that most English persons wouldn't do. I think I've never seen an English person cleaning a toilet". And he goes to a well known part of London that owes its survival to the workers who shouldn't be here. Producer: Paul Grant.