The Home Office has announced that birth certificates are to be used as part of a clampdown on illegal working.

David Blunkett is also studying whether to increase "substantially" the £5,000 fine for each illegal worker employed.

"Illegal working is a modern day slave trade run by organised criminals," the home secretary said.

"It exploits vulnerable people, undermines fair business competition and the minimum wage, deprives the economy of tax and national insurance contributions and acts as a pull factor for illegal immigration to the UK."