Young graduates tell Channel 4 News they are 'treated as slave labour' - but an online fightback gathers strength, with campaigners warning they will go to court to get payment.

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Websites set up by angry and disillusioned graduates are springing up, offering a chance for unpaid interns to talk about their feeling that internships are often nothing more than exploitation.

As Channel 4 News Culture Editor Matthew Cain reports, internships exist in all areas of the workplace but they are particularly popular in the arts. One reason might be that many arts organisations operate as registered charities and, as such, are exempt from paying volunteer national minimum wage.

But cynics might argue that where passion is required to do a job, then this passion will always be open to exploitation.

Campaigners say there is a widespread lack of awareness among employers of the obligation to pay the minimum wage. In April the Low Pay Commission criticised Her Majesty's Revenue & Customs (HMRC) for failing to enforce minimum wage laws on internships.

There is no legal definition of an intern that allows a company to avoid paying someone who is doing defined work in fixed hours. The law states that anybody who qualifies as a worker must be paid at least £6.08 an hour if aged 21. All employers must pay this, and an "intern" cannot waive his or her right to these wages, although there is an exemption in minimum wage legislation for charities and voluntary organisations.

In May the National Union of Journalists helped a former intern, Keri Hudson, win back payment from a company she had interned for, even though she had agreed to work without pay at the time. Their "cashback for interns" campaign aims to win more such victories.

Read more: When does an internship become 'slave labour'

Unpaid internships 'are replacing entry-level jobs'

Alex Try runs internsanonymous.co.uk. He told Channel 4 News that it was his own experiences after graduating from university that drove him to start campaigning: "My girlfriend and I both ended up working for free. At one point we were having drinks with friends, all of us had graduated the previous summer with good degrees and everyone was working for free or applying to do unpaid work. We were just staggered."

Interns don't know that HMRC allows you to claim back unpaid wages up to five years after you worked. Alex Try

"You aren't on JSA, you aren't on official figures, you are between the cracks. We wanted to know how people felt about it, and the response was remarkable. Unpaid internships are gaining prevalance, replacing entry-level jobs - people who can get them are either well connected or have parents who can put them up in London."

Interns and graduates are sharing their experiences of bad practices online and encouraging others to claim the minimum wage for their work where they can.

Young people need to understand what they are entitled to, according to Alex Try: "There have been test cases but interns don't know their own rights. They don't know that HMRC allows you to claim back unpaid wages up to five years after you worked, if you can prove you worked set hours, did set tasks and were relied upon by your colleagues."

And he believes the culture of the internship is spreading out of traditionally hard to enter industries like the media and politics, into areas like retail and administration: "People think of them as being in the desirable professions but increasingly we are seeing unpaid physiotherapists, unpaid jobs in HR, unpaid secretaries. This is the danger, that this spreads."

'Internships exploit those who do them'

Over at Graduate Fog, campaigner Tanya de Grunwald also higlights what she sees as unfair practice, where people are expected to do regular work for no pay, and often engages in debate with companies by writing to them and publishing their responses on the site. She wants to go a step further and help interns take legal action where there are grounds to show that they are doing work that should recieve the minimum wage.

Companies she criticises on her site include Topshop, Reed and Tesco.

The villains are the companies who take something for nothing without giving anything back. Tanya de Grunwald

She says it is vital that young people do stand up for their rights: "There is a myth that unpaid work is somehow the solution to youth unemployment but we see it as part of the problem. Internships exploit those who do them and exclude those who can't afford to. We are clear who the villains are here. It's not the interns or their parents. The villains are the companies who take something for nothing without giving anything back."

Tanya de Grunwald told Channel 4 News that she is driven by anger towards companies who use unpaid workers. "I really hate bullies and that's what these companies are doing. They are bullying a whole generation of young people who don't know enough about their rights. "

"When we find evidence that companies are lying the goal is to bring court action."

In April, the Deputy Prime Minister Nick Clegg said he was setting up a social mobility commission, warning that "birth has become destiny".

As part of the plan, he announced that informal internships for young people in Whitehall would be banned. The government said it would ask all employers to commit to improving access to their internships.