Media playback is unsupported on your device Media caption Boris Johnson has "gone off the rails": Lord Sugar

Apprentice star Lord Sugar has been appointed as the government's enterprise tsar.

Downing Street said the Amstrad founder would be touring the country, championing enterprise and encouraging firms to take on more apprentices.

Lord Sugar previously held a similar role under Gordon Brown's Labour government.

Last year he said he was quitting Labour because of his "disillusionment" with the party.

The businessman said he was "delighted" at his latest appointment, adding that "not enough of our young people know about apprenticeships and what they offer, and too few feel empowered to set up their own business".

Skills Minister Nick Boles said Lord Sugar had "huge credibility among young people".

'Off the rails'

In an interview with the BBC's Newsnight programme, Lord Sugar claimed former mayor of London Boris Johnson had gone "off the rails" in his criticisms of the European Union in recent weeks.

"These people that are advocating exit, with all due respect to them…some of them are politicians, and there's an ex-mayor who has gone off the rails at the moment, I had a lot of respect for him until a couple of weeks ago with some of the outlandish things he has been saying."

Despite being a strong supporter of the UK remaining in the EU, Lord Sugar said David Cameron and other pro-EU ministers needed to substantiate the claims they were making about the economic damage that a vote to leave would do.

"I said to the prime minister the other day you have a whole host of people giving you a load of statistics which you are rattling off.

"If it was me I would say give me the detail so that I can tell ordinary people that I'm not just going to say things like jobs will go, I will want to explain why jobs are going to go. That's got to happen in next two weeks."