'Go home or face arrest' immigration vans

In the UK illegally? Well, go home or face arrest. If you live in one of six boroughs of London - including Hounslow, Ealing, Brent and Barnet - they're the words you'll be seeing on billboards attached to vans driving around over the next two weeks. It's part of a pilot scheme by the Home Office to encourage people here illegally to leave - and let them know if they don't, they will be locked up. They have atttracted widespread criticism. Paul Wylie is head of Home Office's immigration enforcement in London and spoke to BBC Asian Network.