Vans emblazoned with the message "go home or face arrest" are to be driven around London as a warning to illegal immigrants as part of a Home Office crackdown in the capital.
The pilot scheme will see two vehicles display the number of illegal immigrants that have recently been arrested in the area along with a number the they can text to arrange their return.
The vans will be driven around the London boroughs of Hounslow, Barking & Dagenham, Ealing, Barnet, Brent and Redbridge while leaflets and posters highlighting the advantages of returning home voluntarily will be circulated in each area.
The vans will bear the message: "In the UK illegally? Go home or face arrest. Text HOME to 78070 for free advice, and help with travel documents. We can help you return home voluntarily without fear of arrest or detention."
They will be driven around for the next two weeks, with the area chosen because they have either significantly higher or below average numbers of voluntary returns, meaning that the success of the pilot can be assessed.
Material has also been published in local papers and distributed in areas where illegal migrants are known to frequent, including newsagents, money transfer shops and internet cafes.
Immigration Minister Mark Harper said: "We are making it more difficult for people to live and work in the UK illegally. Every single day our enforcement officers are arresting, detaining and removing people with no right to be in the UK.
"But there is an alternative to being led away in handcuffs. Help and advice can be provided to those who co-operate and return home voluntarily.
"This pilot is just another part of the reforms of the immigration system that have cut out abuse and seen net migration drop to its lowest levels in nearly a decade. The Immigration Bill being introduced later this year will build on this work by restricting illegal migrants' access to benefits and services."
The Home Office said voluntary returns are the most cost-effective way of removing illegal immigrants and save the taxpayer money. The pilot builds on the Government's current work on voluntary returns, which saw more than 28,000 voluntary departures last year.