THERE HAS been a major increase in the number of employers prosecuted for hiring illegal immigrants, it was reported today.

In the two months since a change in the law came into effect at the end of February, 137 firms have been caught employing staff illegally.

The figure is 10 times more than the number caught in the whole of 2007, and more than double the number of companies prosecuted in the last decade.

Immigration Minister Liam Byrne told the BBC: "There are dodgy employers out there who are trying to undercut their competitors and drive down British wages by employing people illegally, so we've come up with this new way of taking much faster on-the-spot action.

"It's quite clear that this new regime, which is part of a big shake-up of Britain's border security, is already beginning to work."

Employers face fines of up to £10,000 for each illegal immigrant they employ.

In the last two months fines of roughly £500,000 have been handed out. Persistent offenders also face a jail sentence.

In an enforcement operation seen by the BBC, 60 Borders and Immigration Agency officers raised a chicken processing factory in Derbyshire following police intelligence which suggest illegal immigrants were working there.

Officers found a large processing room with 56 workers, all from overseas, and after several hours of questioning determined that 22 of the workers were illegal immigrants.

The illegal immigrants, from countries including Afghanistan, Pakistan and India, were led out of the building in handcuffs and taken to police stations.

However, only two of the 22 arrested on the raid on the chicken processing plant were deported immediately.

Investigations into the owners of the company, which has not been named, are continuing and so far no fines have been levied.

Since February the broadcaster reports there has been a 40% increase in the numbers of BIA enforcement operations.

But the Government now faces a major headache in dealing with the illegal immigrants it has rounded up.

It can take months to deport an illegal immigrant and is estimated to cost more than £11,000.

There are reportedly hundreds of thousands of people illegally staying in the UK, meaning the Government could be landed with a bill running into billions of pounds.

The Liberal Democrats welcomed the Government's new crackdown on employers, but said it was long overdue.

Home affairs spokesman Chris Huhne told the BBC: "If we are going to be effective in reducing the pull factor of employers employing illegal immigrants then it's not good enough just to have a little blitz with a few prosecutions in one year.

"We've got to sustain this over time and employers have got to realise that this is not a short cut to cutting costs."