It’s not the flashiest mode of transport for a prime ministerial contender, but for Liberal Democrat leader Nick Clegg the car is symbolic of his political stance, one marked by second-class seats on trains and nondescript offices.

He’s here to open a new building at Greystones Primary, in his leafy Sheffield Hallam constituency.

Staff at the school say the 42-year-old has the ‘common touch’ and, as he wanders round the site, it’s not hard to see why they feel that way.

Clegg, whose own mum was a teacher, is easy among people, forthcoming and jovial, regaling staff with tales of previous school visits.

“I visited one school and had a go with a skipping rope. This child overtook me – I was absolutely knackered and struggling for breath,” he laughs.

His visit is brief. It’s Thursday, surgery day, and the Lib Dem leader must return to Nethergreen Road and his constituency office – a modest building at the back of a small yard.

He sits, legs crossed, on old-fashioned pine furniture. “It’s hardly glamorous,” he laughs.

The discreet setting also reflects Nick Clegg’s rather unkind nickname of ‘Invisible Clegg’, which he is quick to dismiss.

“I don’t recognise that,” he says. “I don’t think anyone can reasonably say we have not been right out there in public debate.”

Clegg became MP for Sheffield Hallam in 2005, and his constituency includes some of the most affluent wards in the country.

Since securing the seat, Clegg has divided his time between London and Sheffield, although he says: “I’m a Sheffielder by convert – I moved up here from Nottingham so I’ve got the zeal of the convert!

“I think – and I’m not just saying this – it’s one of the greatest cities in Britain, partly because Sheffield’s less brash than other cities – a little more modest.

“The people are true to themselves. They’re straight with each other. No wonder they call Sheffield the biggest village in the country.”

He admires the city’s diversity – from its thriving cultural centre to the Peak District’s rolling hills, although he admits: “Some of that diversity is tragic. A child born in one of the poorest parts of the city will die an average of 14 years earlier than a child born in a more affluent part of town.”

Poverty is something Clegg can only sympathise with, however. He was educated at the illustrious public Westminster School.

He then studied anthropology at Cambridge University, the University of Minnesota and the College of Europe in Bruges – where he met his Spanish wife commercial lawyer Miriam Gonzalez Durantez.

He worked as an intern in New York on The Nation magazine and later The Financial Times, until entering the political world as the chief of staff for the European Commission from 1994 to 1999.