Channel 4 News reveals one of the countrys largest NHS private contractors may have employed close to 1,000 illegal immigrants as cleaners, catering staff and security in hospitals in the south east.

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An audit by the UK Border Agency of a handful of health service contracts with ISS Mediclean has found that 8 per cent of its workers were illegal, writes Simon Israel.

The move was prompted by a Channel 4 News report last year on ISS staff at Kingston Hospital, and the finding raises questions about the scale of the illegal migrant workforce in the public sector.

Latest estimates by the London School of Economics suggest anywhere between there 400,000-600,000 illegal immigrant workers in the UK, most employed in the twilight zone of the economy - takeaways, kebabs shops, small grocery stores - and most in London and the south east.

But Channel 4 News has found that a snapshot of the public sector has revealed that many hundreds, if not thousands, are working in the NHS alone.

The UK Border Agency carried out an audit of a handful of NHS contracts with its largest supplier of support services, ISS Mediclean Limited, following a report by Channel 4 News last November on the use and possible exploitation of illegal immigrants as cleaners at Kingston Hospital in Surrey.

Immigration officers found that 8 per cent of the 1,500 hundred staff employed in catering, cleaning and security were working illegally.

ISS says it has some 10,000 blue collar staff within the M25, and if those findings were repeated across the board, the company may have around a thousand irregulars, as they are termed, on its books.

But unlike hundreds of other companies which have been fined thousands of pounds since the civil penalty system came into force in February 2008, ISS Mediclean has escaped financial penalties.

UKBA accepts the company's defence of due diligence. In other words, ISS has carried out all the required checks including passports and national insurance numbers.

The company insists: "We have been working with the UKBA to define best practice in avoiding the hiring of workers without the required genuine paperwork.

"We have looked at a number of areas and enhanced our processes accordingly and have made recommendations on how to further improve cooperation with UKBA, at local and regional levels."

The problem, the industry argues, is that they are not experts in detecting forged papers and, more controversially, claim the policy of expulsion isn't working and in fact isn’t even enforced by UKBA.

Last week's case of the attorney general's former housekeeper cleaner Loloahi Tapui showed how clever fakes can be.

This was the forged Home Office stamp in her passport which Tapui said she paid a Russian friend to arrange.

Tapui, who's awaiting sentence for lying about her residential status, was on ISS books until the end of 2007. But her student visa ran out two years earlier, in 2005.

So she was illegally working for ISS for two years and left two months before the penalty system came into force.

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Studio discussion: Phil Woolas, Chris Grayling, Chris Huhne
Immigration minister Phil Woolas, shadow home secretary Chris Grayling, and Chris Huhne, the Liberal Democrat spokesman on home affairs, joined Jon Snow in the studio.

Phil Woolas dismissed the thrust of Simon Israel's report as a "load of tosh" – although he later modified his words to say "your allegation was tosh".

He said: "Last year there were 64,000 removals from this country, so I don't accept the report at all. It's painting one side of the picture."

Chris Grayling replied: "I don't think it's tosh at all. I think this government has failed to deliver when it comes to deporting people who are here illegally."

Discussing the figure of 64,000 removals, Chris Huhne noted that "half of the people who were deported were not actually deported – they were simply turned away at the border.

"This government has failed to dliever when it comes to deporting people who are here illegally." Chris Grayling

"So that's a wild exaggeration of the effort that the UK Border Agency is actually putting into this problem."

He went on to claim that the employers of illegal immigrants were exploiting them and that the government was not doing enough to prosecute those employers.

The Conservative spokesman told Jon Snow: "What we need to do is have a renewed focus within the Border Agency on actually deporting people. We need a dedicated border police force to crack down on the bigger organisers of illegal working."

And Mr Grayling agreed within Chris Huhne that the UK needed to prosecute employers who do take on illegal workers. "At the moment they get the financial equivalent of a parking ticket," he said.

Phil Woolas countered that "the sponsorship regime that we have is resulting in an exposing of illegal immigrant working", and he said the government was prosecuting employers "all of the time".

"The sponsorship regime that we have is resulting in an exposing of illegal immigrant working." Phil Woolas

Chris Huhne repeated his claim that half of those allegedly "deported" were in fact turned away at the border. "The problem," he said, "is that the Labour government has not enforced the law."

Discussing London Mayor Boris Johnson's suggestion of an amnesty for illegal immigrants who had been in the country for five years or more, Christ Grayling said there would be no such provision under a Conservative government. "It sends totally the wrong message to the world."

Phil Woolas was also against an amnesty, while Chris Huhne explained that the Lib Dems were recommending "that if people have been here for 10 years… they can work their way towards citizenship. But that's very different to the proposal of an amnesty."

Grayling on gay rights
At the end of the interview, Jon Snow asked shadow home secretary Chris Grayling to elaborate on comments he made in The Observer in which he appeared to support the right of bed and breakfast owners to ban gay couples.

"I don't think that people who are gay should be turned away from a B&B," he said. "They would be wrong to do that."

Mr Grayling went on to state that he had voted in favour of civil partnerships and that he had changed his view on gay adoption.

"I now support gay adoption," he told Channel 4 News. "The interests of the child come first. I think many gay couples would make excellent carers, parents."