Asked by the Scottish Sun if people can take him seriously after he spent the morning sliding down volcanoes, Rennie was defiant: "I'm having the best campaign of my life, I'm thoroughly enjoying it, and actually politics can sometimes be a little bit fun.

"I'm sorry to say, guys, I know you're reporting on it all the time, but actually having a bit of fun does no harm. We have tackled the big issues in this campaign: investing in education, challenging Amazon on tax, people being paid below the proper living wage, making sure we get proper investment in mental health services."

He added: "You're allowed to do both – you can raise big issues and have a bit of fun at the same time. It's fine, and I noticed you've printed the pictures."