Unite, the UK's largest union, has announced it intends to report leading charities that exploit unpaid interns to HMRC, arguing that this practice is unfair and that HMRC should do more to enforce national minimum wage (NMW) requirements in the charity sector.

Unite, which has 60,000 members in the not-for-profit sector, has given evidence to the Low Pay Commission that it understands that more than a third of the UK's top 50 charity employers are signing up unpaid interns, based on its analysis of Charity Commission data from 2013 and research on website advertisements from leading charities.

Unite's national officer for the sector, Sally Kosky said that many of the charities are multimillion pound enterprises that can well afford to pay.

'Writing to the HMRC is next step in our campaign to stop these exploitative charities trading on the goodwill and compassionate nature of young people.'

'The HMRC is charged with enforcing the NMW and we would urge them to take action where it is clear that young people doing an unpaid intern role are actually doing a proper job of work and should be paid accordingly,' Kosky said.

Unite said that it would not be 'naming and shaming' those charities alleged to be exploiting interns. The union said that it should be up to HMRC, once it had carried out a thorough investigation, to decide whether it wanted to publicise those particular charities.