The force will be made up of existing immigration and passport control officers who patrol ports of entry in plain clothes, along with the staff who implement the removal of illegal immigrants.

John Reid, the Home Secretary, will announce plans for the new force this week, saying that he believes a highly visible presence will act as a deterrent.

He will also announce final plans to reform the heavily criticised Immigration and Nationality Directorate, which will see its budget doubled to £280 million by 2010. The cash will be spent on extra staff for the new force and more raids on businesses suspected of hiring illegal immigrants.

The Conservatives condemned the move as a stunt. David Davis, the Shadow Home Secretary, said: “This is a cosmetic gimmick designed to persuade the public that action is being taken when the necessary serious action is being baulked at.”

Speaking on GMTV, Mr Reid said that progress had been made on asylum, and illegal immigration was now the target. “We are deporting more failed asylum-seekers than are coming to this country. But we need to do more and I intend to do more.

“I want to strengthen the resources for our border enforcement. We need a better, more forceful, more effective, more visible border enforcement.”

He will make a Commons statement tomorrow. However, it will be overshadowed by new accusations from MPs concerning the extent of corruption in the immigration system.

The Home Affairs Committee found that there were more than 700 allegations of corruption made between 2000 and 2005, leading to 409 investigations. As a result, 31 employees have been referred for prosecution and 79 for disciplinary action.

The findings come only months after Tony McNulty, a former Immigration Minister, said that cases of corruption were “isolated incidents”.

Mr Reid will also be questioned on Home Office estimates that up to 140,000 Romanians and Bulgarians will arrive in Britain when the two countries join the EU next year.

More than 600,000 came from the eight countries that joined the EU in 2004, compared with the Government’s estimate of 13,000. The Home Office is thought to be particularly concerned about criminal elements coming to Britain.

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