Lib Dem candidate Richard Foord was elected as the new MP for Tiverton and Honiton in the early hours of this morning (24 June) in a landmark election result.
The party overcame a huge Conservative majority to win by more than 6,000 votes in the poll caused by the resignation of Conservative Neil Parish after he was caught viewing pornography on his phone in the House of Commons.
Fearnley-Whittingstall said he decided to vote for the Lib Dems so his vote "might actually have an impact" on the electoral system.
Posting on Twitter before the result was announced, he explained: "I’m voting in the Honiton and Tiverton by-election today. And I’m afraid I’m going to break a pledge I made a year ago, when I joined the Green Party. I said I was fed up of voting tactically and made a commitment to vote Green at every opportunity.
"I simply wanted my green vote to be counted, even when I knew I couldn’t really make it count.
"A system where one million General Election votes gets the Tories 20 MPs but the Greens only 1 is a grossly unfair system.
"So unfair that there are times when the opportunity to “game it to change it” becomes almost impossible to resist. Today I have such an opportunity, a chance to cast a vote that might actually have an impact on that system.
"It’s going to be very tight, but if we can unseat the Tories here today we can, in a small but not insignificant way, shift the dial towards a progressive alliance and perhaps ultimately a more representative democracy.
"And so, with apologies to my friends in the Green Party, of which I remain proud to be a member, today I will be voting for the Lib Dems. I will not feel as good or as honest as I would voting green. But in a contest that could well go to the wire, I feel it’s what I have to do."
Speaking after his election win, Mr Foord insisted "the people of Tiverton and Honiton have spoken for Britain."
He said: “They’ve sent a loud and clear message: It’s time for Boris Johnson to go and go now."
After the results were announced, the Prime Minister said he recognised that voters are "going through a tough time at the moment", and said he will "listen" to voters but "keep going".
Want a quick and expert briefing on the biggest news stories? Listen to our latest podcasts to find out What You Need To Know