Mark Logan has become the third Conservative candidate to defect to the Labour party in the latest blow for Rishi Sunak.
The former MP for Bolton North East is urging people to vote Labour in the general election on July 4.
Over recent months, Logan has condemned the Government over Gaza as he calls on the UK to recognise Palestine as a country.
He said the Tory Party was "unrecognisable" from the party he joined a decade ago.
The former MP for Bolton North East is urging people to vote Labour in the general election on July 4
PA
He wrote in a statement: "Labour is back, and given how things have been, I believe things can only get better.
"After much soul-searching throughout my first term in parliament, brought to a head with the calling of a snap election last week, I have concluded that we need a new Government and I believe the UK will be best served with that Government being a Labour Government.
"We need renewed enthusiasm and optimism in both tone and in policy, and I believe that we are already seeing this through Keir Starmer and the team.
"I am resigning from the Conservative Party with immediate effect. Regrettably, I will therefore not contest our constituency at the upcoming General Election."
In 2019, Logan won his seat from Labour with a majority of just 378.
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The seat had been Labour since 1997 but was previously held by the Conservative Party.
The former UK diplomat serving in China - who is fluent in Mandarin and Japanese - claims Labour could "bring back optimism into British life".
Logan is not a candidate at the General Election but has not ruled out running for Labour in the future.
"When I look back to my teenage years, in 1997 when Labour came to the fore at that time and we obviously heard the song Things Can Only Get Better, I feel that we're at that point again in British politics and British history," he told the BBC.
"For my constituents and for the country, it's right that we get some stability back into the UK, we get optimism, we get new and fresh ideas.
Mark Logan's defection comes after two other MPs - Natalie Elphicke and Dan Poulter - also quit the Tory Party to join Labour earlier this month
PA"I believe, as a politician, it’s incumbent upon me to be able to say, to look people in the eyes in Bolton and say that I believe that a Labour Government is going to serve you better, your interests better, it’s going to be better for your pockets, it’s better for the economy, it’s going to be better for the UK."
Following the Hamas October 7 attacks on Israel, Logan - whose constituency has a large Muslim population - has been critical of UK policy and the actions of the Israeli government.
In response to the move, a Tory spokesperson said: "It’s notable that Mark Logan has defected to a party he can’t even name a single policy of. We wish Mark Logan well with the Labour Party - a Party that has no plan for the country and would take us back to square one."
His defection comes after two other MPs - Natalie Elphicke and Dan Poulter - also quit the Tory Party to join Labour earlier this month.
