Nick Clegg reveals he owns a ‘onesie’ – in response to question from Old Etonian ‘King of the Liberals’ who used to work for him

The question regarding the 'onesie' came in a light-hearted exchange following thirty minutes of critical and at times heated debate

The Deputy Prime Minister Nick Clegg has revealed he was given a 'big green onesie' as a gift - but has never worn it.

The Liberal Democrat leader was speaking during his first weekly phone-in show on the London-based talk radio station LBC. Mr Clegg, who said the 'onesie' was still in the packaging, joked he would only wear it in the privacy of his own home.

But the question regarding the 'onesie' from a “Harry from Sheffield” – which formed part of a light-hearted exchange following thirty minutes of critical, and at times heated, debate between Mr Clegg and callers – was not all it seemed.

In fact, the caller was Harry Matthews, a student Liberal Democrat activist who worked in the Deputy Prime Minister’s office over the summer. Matthews claimed that he gave Mr Clegg the garment at a party event several months ago, and posted a picture on Twitter as confirmation.

Mr Matthews, 20, is acting chair of the national organisation Liberal Youth and a Physics undergraduate at the University of Sheffield, in Mr Clegg’s constituency.

Mr Clegg was earlier confronted by a former Liberal Democrat councillor who told him he had torn up his party membership card because he was ashamed of what they were doing in Government.

The caller, John, from Woking, told him: “I'm a Liberal Democrat who's just torn up his membership card.

“I joined in 1973 and I'm afraid I can't now say I want to represent the Liberal Democrats. I'm an ex-county councillor in Surrey and I am ashamed of what the party's doing.”

Mr Clegg has said he is doing the programme, with presenter Nick Ferrari, because he feels politicians do not hear enough from voters directly, and one caller told him his decision to take part was “very commendable”.

Mr Clegg asked John to give the party credit for measures like raising the income tax threshold and introducing a pupil premium for children from disadvantaged backgrounds.

He insisted: “I am immensely proud that, facing the biggest crisis this country has seen in a generation, the Liberal Democrats took a big, collective and brave decision - at some political cost - to say we are going to step up to the plate... and fix this mess while also trying to make society fairer.”

Another caller, a Sheffield University student called Lauren, dismissed measures like the pupil premium as "tokenistic" and accused the Government of discouraging young people from gaining qualifications by abolishing the educational maintenance allowance and increasing tuition fees.

"It seems as if the coalition is trying to tell them that higher education is not for them," said Lauren - a charge Mr Clegg did not accept.

The Deputy Prime Minister repeated his apology for committing the Lib Dems not to raise tuition fees when they were not in a position to deliver on the promise, and he admitted the party's recent eighth position in the Rotherham by-election was a "woeful result".

But he said it was always going to be "monumentally controversial" for them to enter coalition with any other party, and said voters were willing to give their support when they had a chance to explain their actions.

"Where we can get on to people's doorstep or in front of a radio mike and explain to people what we are doing, why we are sticking to our guns on some of the big decisions, why the country has to go through this difficult process, I'm finding that people - perhaps not with bunting and wild-eyed enthusiasm - recognise that what we are doing is the right thing," he said.

"What I'm trying to do is build a strong economy and a fair society."