Science minister and Mid Norfolk MP George Freeman has refused to confirm his support for Boris Johnson ahead of a confidence vote in the prime minister's leadership tonight.
While Mr Freeman has not revealed which side he will be on in the vote on the PM's future, he said it will be critical for the government "to command public trust and confidence".
He is thought to be the first government minister to have publicly signalled that he could be joining the anti-Johnson rebels.
Approached for comment, Mr Freeman said: “The country is facing huge challenges - from the horrific Russian attack on Ukraine exacerbating global inflation, a cost of living crisis and risk of recession.
"The government will have to take some very grave decisions in the coming months, for which it will be critical to command public trust and confidence.”
In comments following the publication of Sue Gray report into parties held at Downing Street during lockdown, Mr Freeman had called for “serious changes” to be made to “repair damaged public trust", but he confirmed at that time that he was not calling for the PM's resignation.
In the time since then, several of his Conservative colleagues have publicly said they believe Mr Johnson should resign.
On Friday last week, booing could be heard coming from a crowd of people outside St Paul's Cathedral, as Mr Johnson and his wife entered and exited the Queen's Platinum Jubilee thanksgiving service.
Mr Freeman later told a journalist, who speculated on Twitter whether he had become the "first minister to break cover and signal they'll vote against" Mr Johnson, that that was "absolutely not what I said or intended to 'signal'".
He later complained that his refusal to specify whether he was supporting the PM had been subjected to the interpretation of others, and that he simply wished to avoid getting drawn into the "media feeding frenzy with open speculation on Twitter about my vote in what is a secret ballot of Conservative MPs".
And following a meeting with the 1922 committee of Conservative MPs, Mr Freeman tweeted that he had witnessed "a serious and statesmanlike appeal from the PM... not to descend into fratricidal infighting but focus on delivering the priorities we won a majority for in 2019, and that he is committed to restoring trust & leading the country, government and party in unity."
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