Businesses are harming their interns’ career prospects by paying them nothing, according to a new YouGov poll, after leading UK internship marketplace Enternships announced a ban on employers listing unpaid vacancies.

Commissioned by campaigning group Intern Aware, the YouGov study of 682 businesses found that 48% of employers who paid interns regarded internships as a valuable recruitment strategy for full-time employees, compared to just 32% of companies who did not pay their interns.

Further, 82% of businesses using unpaid interns admitted they could perform tasks that were useful to their business, representing a potentially widespread breach of minimum wage regulations.

Intern Aware said the widespread use of unpaid internships was not only unfair on the interns concerned, but also excluded those on lower incomes who could not afford to support themselves throughout an unpaid work placement.

There are approximately 100,000 unpaid interns in the UK, according to data from think-tank IPPR, which Intern Aware said showed that the practice has become an accepted norm.

The practice has recently been the subject of focus in Parliament after Conservative MP Alec Shelbrooke proposed a motion to introduce a four-week limit on unpaid internships to provide employers with a clear signal as to what is acceptable in the eyes of the law.

Ben Lyons, co-founder of Intern Aware, commented: “Unpaid internships exclude the vast majority of young people who can’t afford to work for free. As well as being morally wrong, unpaid internships are bad for business, as employers are only able to draw from a small talent pool.

“The Government should address this problem by introducing a new four week limit to unpaid internships. A four week limit would provide fairness to young people and clarity to employers.”

The results come as leading online internship marketplace Enternships announced a site-wide ban on unpaid vacancies, which it said would force its 6,000 client employers to support fair internships or leave the site altogether.

Rajeeb Dey, founder and chief executive of Enternships, explained the decision: “In this day and age it’s simply unacceptable for talented young people to be exploited and not paid for their hard work.

“Where an intern is working for a company and clearly adding value they should be treated as any other worker and paid in accordance to the National Minimum Wage. It is clear from today’s research findings that employers who pay their interns value them more, and are more likely to offer them full-time employment.

“By banning the advertisement of unpaid roles we hope interns are hired on their ability alone rather than whether they can afford to work unpaid and encourage employers to create more meaningful internship opportunities whereby both the intern and business can realise its value.”