Boris Johnson, the frontrunner to become the next prime minister, has said he makes models of buses out of old wine crates to relax.

The former mayor of London, whose term in office included the introduction of the new “Boris bus” to the capital’s streets, said he liked to unwind by painting passengers enjoying themselves on his model vehicles.

“I like to paint or I make things,” the Tory leadership candidate told TalkRadio.

“I get old wooden crates, right? And I paint them.

“I suppose it’s a box that’s been used to contain two wine bottles.

“It will have a dividing thing, and I turn it into a bus and I put passengers…

“I paint the passengers enjoying themselves on the wonderful bus. Low carbon, of a kind that we brought to the streets of London that reduces CO2, reduces nitrous oxide, reducing pollution.”

Mr Johnson’s meandering explanation provoked discussion and a little confusion on social media.

A clip of the BBC news presenter Simon McCoy reacting to his comments was particularly popular with Twitter users.

EU referendum
Mr Johnson on the Vote Leave campaign trail in 2016 (Ben Birchall/PA)

“Wonder what he writes on the side of it,” the newsreader said – a reference to the infamous £350 million figure on the side of a campaign bus during the EU referendum.

Conservative MP Sir Nicholas Soames responded by suggesting Mr Johnson should have stuck with the famous “fields of wheat” line, which Theresa May once offered as the “naughtiest” thing she did as a child.

Sir Nicholas, the grandson of Mr Johnson’s political hero Sir Winston Churchill, tweeted: “#stickwithwheatfieldsifiwasyou”