The UK's governing Conservative Party has suffered a further blow after a former outspoken MP and Speaker of the House of Commons defected to the Labour Party.
John Bercow's decision comes shortly after the Tories suffered a significant defeat in a parliamentary by-election in a supposedly safe Conservative seat on Thursday.
The Conservatives under Prime Minister Boris Johnson are "reactionary, populist, nationalistic and sometimes even xenophobic," Mr Bercow said, in an interview with The Observer newspaper.
During his tenure as Speaker, Mr Bercow, 58, faced accusations of favouring "remainers" in Brexit debates in the lead-up to the UK leaving the EU.
He said the current government “needs to be replaced”.
Mr Bercow stood down in 2019 as Speaker after a decade in the role and had been an MP since 1997.
The Speaker has to be politically impartial and he had to resign from the Conservative Party when he was elected Speaker in 2009.
But he subsequently had many rows with his former party, including in 2015 when he survived an attempt by Conservative officials to oust him.
“I am motivated by support for equality, social justice and internationalism,” Mr Bercow said.
“That is the Labour brand. The conclusion I have reached is that this government needs to be replaced.
"The reality is that the Labour Party is the only vehicle that can achieve that objective. There is no other credible option."
He told the newspaper he joined Labour a few weeks ago.
Mr Bercow also described Mr Johnson as “a successful campaigner but a lousy governor”, who had contempt for Parliament.
At the end of his tenure as Speaker, Downing Street declined to put forward Mr Bercow for consideration for a peerage in the House of Lords – the upper house of the UK legislature.
Instead, the Labour opposition nominated him.
Mr Bercow said it was "blindingly obvious" that there was a "concerted campaign" to prevent him from being given a peerage, a position conventionally offered to former Speakers.
He said the Conservatives' loss of the Chesham and Amersham parliamentary seat in last week’s by-election showed there was “considerable distrust on the part of voters in the south of England of this government”.