Top Conservative Boris Johnson resorted to schoolyard taunts during the latest leg of his pro-Brexit battle bus tour around UK on 16 May. The former Mayor of London claimed 'Remain' campaigners like David Cameron and George Osborne had their "pants on fire" over the forthcoming referendum.

"When you look at the EU now, it reminds me of some badly designed undergarment that has now become too tight in some places – far too right, far too constrictive – and dangerously loose in other places," Johnson declared, as he visited a women's wear factory near Nottingham.

"I just say to all those who prophesise gloom and doom for British business, I say their pants are on fire. Knickers to the pessimists, how about that? Knickers to all those who talk Britain down.

"Let's take back control of huge sums of money, take back control of immigration, take back control of our democracy, let's vote for freedom on 23 June and I believe that 24 June will be Independence Day."

The Vote Leave spokesman made the comments just hours after Osborne, former shadow chancellor Ed Balls and former Liberal Democrat business secretary Vince Cable united to warn of the economic implications of a Brexit. The Tory chancellor mocked Brexit campaigners, suggesting they were conspiracy theorists.

"The next thing we know, the leave camp will be accusing us of faking the moon landings, kidnapping Shergar and covering up the existence of the Loch Ness monster," he quipped.

"The response to the sober, economic warnings from around the world by those who want to leave the EU has not been credible or serious. And there's a reason that the three of us are standing here today, putting aside our very obvious differences. It's not a conspiracy, it's called a consensus."

Elsewhere, Johnson was forced to defend his comparison of the EU to Nazi Germany. The Brexit campaigner reportedly blamed media "hysteria" for the controversy.

"This discussion is bedevilled by all sorts of artificial media twit-storms or hysteria of one kind or another. There's a very good argument against the lack of democracy in the EU," Johnson told the BBC News channel.

"Over the last 2,000 years people have made repeated attempts to unify Europe by force. The EU is a very different project but it is profoundly antidemocratic."