The UK government's social mobility tsar has called on professional employers to axe unpaid internships in order to ensure fair access to Britain's top jobs.

Labour MP Alan Milburn argued, as part of an agenda to tackle the plight of the "forgotten middle class", that the growth in professional employment is not creating a new "social mobility dividend" for the UK.

Milburn, writing for New Labour pressure group Progress, claimed that Britain's top jobs are dominated by a "social elite" and unpaid internships go to young people on the basis of "who, not what, you know" as well as disadvantaging people from backgrounds who cannot afford to work for free.

"Nearly one-third of MPs, more than half of top journalists, and 70% of high court judges went to independent schools, though only 7% of the population do so," Milburn stressed. "This is social engineering on a grand scale."

The influential MP also called for the national minimum wage, which currently stands at £6.31 ($10.15, €7.52) per hour for over 21s, to be increased.

"The working poor are the forgotten people of Britain," Milburn said. "They need a new deal. The minimum wage is worth £1,000 less in real terms today than it did in 2008."

Milburn also suggested, among other things, that colleges should receive performance based pay rather than recruitment number, and that the "best teachers" who work in the "worst schools" across the country should have a pay increase.

"It is in Britain's DNA that everyone should have a fair chance in life. Yet too often demography is destiny. Over decades we have become a wealthier society but we have struggled to become a fairer one," he said.

Milburn's comments come just a day after Labour Party Leader Ed Miliband delivered a keynote speech in London which set out a wide-ranging platform and was tipped as the official start of his party's election campaign.