The Conservative Party says MP Lucy Allan has been suspended for backing a Reform UK candidate.
Ms Allan insists that she quit the party in order to support Reform UK candidate Alan Adams in the seat she is vacating.
She publicly gave her support to Mr Adams rather than Tory Hannah Campbell in Telford, Shropshire.
A Conservative Party spokesman said she had been suspended “with immediate effect”, and that “a vote for Reform is a vote for Keir Starmer”.
Mr Adams would offer an alternative to “more of the same politics and more of the same politicians”, Ms Allan said.
She won Telford in 2019 with a majority of 10,941 but in 2017 the Conservatives won by 720 votes – and she first won the seat in 2015 with a majority of 730.
The MP stated that she had known Mr Adams for many years and that the Royal Navy veteran “is genuinely the best person for the job”.
Ms Allan said: “I want the best for Telford and I can’t just let the Labour candidate have a walkover.”
She added Mr Adams was “not in it for personal advantage, power, or control over people” and his motivation for standing “is profoundly honourable”.
Ms Allen said: “Alan gives Telford a choice, so that Telford does not have to settle for more of the same politics and more of the same politicians.”
The Tory spokesman said, following Ms Allan’s suspension, “the people of Telford now have the chance to vote for a dedicated and hard-working new candidate who will put Telford first”.
Asked about Ms Allan’s revolt, Prime Minister Rishi Sunak said “when it comes to Reform, I understand people’s frustrations”.
But he added a vote for other parties “particularly Reform, all that is going to do is put Keir Starmer in power”.
A Reform spokesman said the party was “absolutely delighted” Ms Allan was backing their candidate.
“She, like many Conservatives, feels that the Reform party represents traditional centre-right values and priorities in a way that the Conservative Party has long forgotten,” they added.