A tuft of grey chest hair pokes out of the top of Alan Kean's stripey shirt. It catches my eye as we drink tea amid the deafening chatter and the expensive fig trees in Portcullis House where Alan, 55, is six months into life as a parliamentary intern.

In recent months there has been much gnashing of teeth over young people flooding into these positions, unpaid or poorly paid, with scant observation of working rights, desperate to get a foot on the career ladder. That has left little room for discussion around a lesser-known trend: of the 457,200 apprentice positions started in 2010-11 in the UK, 182,100 were started by people aged 25 or over, according to the Data Service. Five years ago, only 300 people aged 25 or older took up these roles.

Of the overall rise between 2006-7 and 2010-11, 68% were in the 25-plus age group, according to the National Audit Office (NAO); an increase it attributes to Tony Blair's government, which, in 2003, widened the age eligibility criteria for government-funded, private company-run apprenticeships to include over 25s.

Many people presume that interning, or being an apprentice (the two are used almost interchangeably) is for graduates or school leavers only and the newly-launched National Careers Service doesn't disabuse would-be applicants of that notion.

Jobs websites bring up advert after advert seeking "ambitious graduates" with a "work hard, play hard attitude" to fill numerous unpaid or minimum-wage internships and apprenticeships – wording that barely complies with age-discrimination law and makes plain the cultural advantage younger, cheaper applicants have over older ones. Part of the problem is that the National Apprenticeships Service pays up to 100% of the training cost of placements taken by 16-18 year olds, and up to 50% for ages 19-24, but makes only an unspecified "contribution" for placements taken by those aged 25 or over.

"The impression is that the government doesn't provide routes for older people like that. We know there's no such thing as a job for life anymore, but culturally, we're yet to develop that broader attitude," says Rosemary Thomas, a research assistant at the Work Foundation, previously a work psychologist at Jobcentre Plus.

"At Jobcentre Plus I worked with lots of long-term unemployed, or over-25s that hadn't worked out what they wanted to do. An apprenticeship or internship would have been a perfect solution for them, but it was so hard to come across anything. We tended to guide them down the voluntary route."

What kind of people make "mature interns"? A Leicestershire boy who left school with no qualifications, Kean fell into hotel work and meandered through "low administrative level" jobs in the NHS and the local branch of the Department for Work and Pensions, later working in the community football stadium in Doncaster where he and his wife relocated, before moving again to London. After a short employment contract with Harrods, he worked as a volunteer with Locog interviewing other potential Olympics volunteers. Then he saw that the Social Mobility Foundation was offering nine-month internships working for parliamentarians, paying £17,500 for that period.

"I did wonder if I was too old to apply because most interns are 18-25, aren't they?" says Kean. "Once upon a time someone like me would be at the end of their working life. But I'm not ready to lie down," he adds. "Like most working-class people I've not had a career, but I've shown in my work that I can do almost anything – I'm flexible and the labour market has a need for that. Being stuck in a rut is a luxury of years gone by. The more strings you have to your bow, the easier it should be to find paid work."

The forthcoming rise in retirement age makes refreshing your skills and competitiveness important. And while older interns and apprentices are doing that, they're providing the UK taxpayer with value for money. In a February 2012 report, scrutinising the government's apprenticeship programme, the NAO found that its advanced and intermediate apprenticeship models produce returns of respectively £21 and £16 for every pound of public funding they receive (the Department for Business, Innovation and Skills estimates those returns at respectively £24 and £35, using a different calculation).

At 27, Ben Harford is an older intern, one of many thousands trying to break into the creative industries, where, though much criticised, poorly-paid internships are all but mandatory. Redundancy last Christmas brought a small sum of cash that Ben ploughed into a career change, retraining from public sector administration to graphic design. A Gumtree advertisement led him to a full-time internship designing sponsorship collateral for a Premiership football club. The commute costs him £500 a month, taking up most of his minimum-wage salary, and he relies on his girlfriend's income to shore up their living expenses.

The work is enjoyable, says Ben, but could end at any time. "It was meant to be six weeks, but it always gets extended for another week, another two weeks … they keep their cards close to their chest, so you're always in limbo," he says. "In this industry you've got to earn your stripes by working for not much money. Even junior positions expect one year's experience. So you've got to start with an internship." His fellow interns, most of whom graduated last summer, "have rich boyfriends or live at home rent-free – they can enjoy being 21 and survive on the minimum wage with their parents' backup. They don't have the responsibilities I've got."

But it can work. Mike Mann was 39 when he joined Pricewaterhouse Coopers' Headstart scheme in 2007 – its equivalent to a graduate scheme, but for those without many formal qualifications – leaving behind a long-established career in sound production. Apprentices are paid a salary to work full-time and study for their accounting qualifications.

He now manages audits for the businesses he was attached to when he started. "I was fed up working in an environment where we were incredibly experienced technically and commercially, but had no real business understanding. I wanted to understand what makes businesses succeed and felt strongly that I needed a mixture of hands-on work and formal training," says Mann. "It was very daunting at first, but being in an environment where everyone is enthusiastic about learning is so refreshing."

He adds that one of his oddest apprenticeship experiences was revising for exams at the kitchen table alongside his daughters who were studying for their GCSEs and AS levels: "Not what you expect to be doing at 40."

The Headstart scheme pays between £16,000 and £20,000. Can an older apprentice survive on that? "This has been the hardest part, but in less than five years I'm back to a healthy salary and over the next few years it will easily surpass what I could have earned before changing career," Mann says.

The NAO report says that completing an advanced apprenticeship is associated with raising earning power by 18%, and completing an intermediate internship raises salaries by 11%.

The cultural barrier to older people accessing these positions remains strong. Some think employers presume they will want too much money, defend their workers' rights too strongly or even show them up professionally. "Employers might be put off because they think they'll expect lots of money, but they might have come out of a well-paid career and aren't motivated by money any more," says Rosemary Thomas.

Kean, the oldest participant on the parliamentary interns scheme, agrees. "So many MPs and their interns have no expertise and haven't worked anywhere else, so I've brought in some procedures here to make things run smoothly," he says. "But I think some employers might be intimidated by someone a bit older with a mind of their own like that. We're more likely to stand up for ourselves, while young workers are new to the workplace and don't know what's expected of them – which is why they are abused."

The government intends to invest more in apprenticeships, and given the return on investment older participants appear to provide, it makes sense to give them more funding.

But Chris Ball, chief executive of The Age Employment Network, sees the cultural blockade at its strongest within the government's apprenticeship machinery. "There are huge issues around economic inactivity among older people, and the fact is the government has put far more energy into supporting young workers than older workers," he says.

"Older people need to feel there is somebody out there working for them, but they're just not a priority – they have to wait six months before they're allowed onto the Work Programme, in which time demoralisation and self-pity can set in. You'll look like a far better prospect to an employer if you're doing something like interning than if you're out of work."

Case study: the translator

Well travelled and multi-lingual, Marta Rodriguez, 34, is the epitome of the progressive European prepared for tomorrow's labour market. A BA twice over, and currently studying an online Master's degree as a mature student, she is highly experienced in translation work.

She is halfway through a six-month internship with a west London translation company, on a scheme operated by the European commission which aims to "help students to adapt to the requirements of the EU-wide labour market".

For Marta, it's a shrewd way to see how her translation clients work from the inside while getting paid. The position was advertised unpaid except for €500 for living costs. But Marta got lucky: her employers pay her £500 per month on top. "They're happy because I think they were expecting an intern with whom they had to spend a lot of time teaching and explaining things."

Marta is the agency's first intern and is seven years older than her manager.

"At the beginning they thought I'd be working on their database all day long, but I'm translating, I'm proof-reading translations from our freelance translators, and I'm about to do some project management," she explains.

"They weren't expecting me to be as experienced as I am or to know what I'm doing. They can rely on me and delegate things.

"I hadn't even thought about the possibility of being an intern before. I thought my employer Erasmus wouldn't accept me because of my age – that they might think 'oh, she must be a loser'," Marta admits.

"That's about my preconceptions – that there's an established way. You finish university, you do your internship, then you get a job, you get a better job and that is what you do with your life – so I thought that was how society would behave towards me."

Article from Guardian