Robin Corden, 42, an account manager for a flooring company, had brought a banner to the Tiverton and Honiton by-election count reading: “The party’s over prime minister.”
He told the Press Association: “I think the greased piglet that is our Prime Minister was very happy to have the vote of confidence before the two by-elections here and in Wakefield.
“Many more backbench MPs would have voted no confidence if they had witnessed the election annihilation that has taken place today.”
Mr Corden added: “Boris Johnson grew up not far from here in Winsford (Somerset), we in the Exe Valley, which has such beautiful orchards, feel embarrassed to have produced such a rotten apple.”
When asked if he believed the Tories really had suffered “annihilation”, Mr Corden replied: “I hope so, I am a Green and I’ve voted tactically.”
He continued: “I decided that I could not live with myself if I woke up tomorrow morning and the Tories had won by a really narrow margin, so I forsook my political loyalties to send a message to the Conservatives that their days are numbered.”