Ministers are cracking down on bogus language collages acting as illegal migration fronts.

Nearly 500 institutions will be banned from taking on foreign students after failing to reach Home Office standards.

Officials would not name the collages but many are in London.

Visas - 'licence to recruit'

There have been fears that collages were effectively being paid to hand out student visas - offering next to no education to get people into the country who would not normally meet migration standards who then disappeared.

More than 1,400 institutions, including elite Russell Group institutions like London's UCL and Imperial College, have qualified for the new 'licence to recruit" but of the 2,100 that applied, nearly 500 failed.

Home Secretary Jacqui Smith said:

"I have made it clear that I will not tolerate either the fraudulent applicants trying to abuse Britain's immigration rules, or the dodgy colleges that facilitate them. However Britain will always welcome legitimate students who are coming here to receive a first-rate education."

Institutions are now responsible for ensuring students return home, and they could lose their licences and face fines if students abscond.