Andrew Rosindell has become the second Conservative MP to defect to Reform UK within a week.
The MP for Romford, Essex, announced on Sunday evening he had decided to resign from his position as a shadow foreign office minister in Kemi Badenoch's frontbench and as a member of the Conservative Party.
The move came after former senior Tory Robert Jenrick defected on Thursday. It takes the total number of MPs in Reform UK to seven.
Both Nigel Farage and Mr Jenrick welcomed Mr Rosindell to the party, calling him a "patriot".
Mr Rosindell, who has been an MP since 2001, said it was time to put "country before party" in a statement announcing his defection.
"Since joining the Conservative Party at the age of 14, I have been a loyal and committed supporter of the principles advocated by Margaret Thatcher that have always underpinned my own political beliefs," he wrote.
"However, the time has come to put country before party.
"The failure of the Conservative Party both when in government and more recently in opposition to actively hold the government to account on the issue of Chagossian self-determination and the defence of British sovereignty, represents a clear red line for me."
A Conservative Party source said Mr Rosindell had threatened to defect for months but denied he was doing so until as recently as Saturday.
"The Conservative Party supported Rosindell throughout his many troubles, and he's responded by stabbing his friends, colleagues and activists in the back. Reform are welcome to him," the source said.
Meanwhile, Labour Party chairwoman Anna Turley said the "stench of a failed and drying Tory party engulfs Reform" and a spokesperson for the Liberal Democrats said Mr Rosindell's defection "isn't a political earthquake".
"It's a change of rosette for a career politician worried about getting a P45," they said.
"The public are fed up hearing about how Britain is broken from the very same people who broke it."
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Following the defection of Mr Rosindell, Mr Jenrick and, before that, former Conservative chancellor Nadhim Zahawi, Tory leader Kemi Badenoch said she was "100% confident" she would not see any more of her shadow cabinet leave for Reform.
It comes as the party, headed by Mr Farage has set 7 May - the date of crucial local elections in which they hope to make significant gains - as a cut-off point for admitting current and former MPs, as well as for local councillors to defect.
Asked if she would be on alert for MPs seeking to switch sides before the elections, Ms Badenoch told the Press Association news agency: "I think people should be wondering why they set that deadline."
(c) Sky News 2026: Conservative MP Andrew Rosindell defects to Reform UK
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