Andrew Bridgen, 57, appeared on the BBC Newsnight programme to discuss the waning support from inside the Conservative Party for Boris Johnson, 57. However, during his interview with journalist Faisal Islam, 44, the North West Leicestershire MP was joined by an uninvited guest.
A placard-wielding activist appeared in shot and could be heard shouting over the Brexit-backing MP.
Pro-EU activist Steve Bray, 52, who was unable to retain his deposit when he stood as the Liberal Democrat candidate in the Leave-voting Welsh seat of Cynon Valley in the 2019 General Election, held up one placard which said: “A crock of s**t.”
When Mr Islam brought up the “distraction” behind Mr Bridgen on College Green, the MP described Mr Bray as a “village idiot”.
However, Mr Bray replied: “No, the village idiot is in front of the camera.
“A liar, a cheat and a charlatan.”
While the Tory MP and Newsnight host attempted to continue their interview, Mr Bray added: “That’s you Mr Bridgen.”
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When the interview came to a close, Mr Islam apologised to BBC Newsnight viewers.
“I must apologise for the language in the poster behind you there,” he said.
Mr Bray held up other placards during the interview.
One read: “Save our democracy.”
Others said “get your Johnson out of democracy” and “toxic Tories destroying our nation”.
Mr Bray had protested against the UK leaving the European Union since September 5 in 2017.
He was heard heckling MPs, journalists and Brexit-backing campaigners in his EU top hat.
However, after 847 days, Mr Bray appeared to concede defeat.
Speaking after the 2019 General Election, he said: “The fight goes on but our future campaigning will be about holding government to account and when the proverbial s**t kicks in, we will look into how we can get back into the EU.”
During Mr Bridgen’s interview with Mr Islam, the Tory MP said he had been inundated with emails following his announcement he had handed in a letter of no confidence letter against Mr Johnson to the 1922 Committee.
Mr Bridgen, who backed Boris Johnson in the 2019 Tory leadership contest, said he had received over 1,000 emails on Saturday alone.
When asked if, as other MPs have suggested, Barnard Castle prompted an even larger backlash, he added: “No, this is the most emails that I’ve personally had.
“I can’t speak for other MPs but I’m sure their inboxes are rather similar.”
Mr Bridgen also called on civil servant Sue Gray, 64, who is investigating ‘partygate’ to bring witnesses, including ex-Vote Leave supremo Dominic Cummings, 50, into her inquiry.
Mr Johnson has been accused of throwing out some “red meat” policies to bolster his support for the Conservative Party.
However, the North West Leicestershire MP appeared sceptical about the Prime Minister’s overtures.
“I find it a little bit patronising,” he said.
“Most of this was in our manifesto and we should have been putting up with it anyway.”