Robin Grey is taking his message on tour.
On Monday a busker sang "Fuck off back to Eton" to David Cameron.
The minstrel got people excited at the prime minister's campaign walkabout in Alnwick, Northumberland, which was captured by ITV.
"Cameron literally only had about 20 people there with blue balloons and posters, and it was all so staged," Grey told BuzzFeed News.
"I thought, 'What happens if we have a people's gathering in King's Cross, with blue balloons and mock-up Tory placards, and show what a real gathering of people looks like, rather than this pathetic staged Tory party nonsense."
He was in the northeast to celebrate his grandmother's birthday, and hadn't planned on picketing the prime minister.
"The Conservative party bus nearly knocked me over on my bike, and then when he got out the bus he had loads of people standing round him with balloons like a children's party, and I thought maybe he'd like a song," Grey said.
"He didn't look like he'd had a good 'fuck' in ages so I gave him a few."
Chris Stokel-Walker/BuzzFeed News