Rishi Sunak will reportedly appoint a new defence secretary later on Thursday, replacing Ben Wallace.
Mr Wallace announced last month he would resign from the senior Cabinet role at the next reshuffle, bringing to an end his four years in the job.
After weeks of speculation over who might replace Mr Wallace, the BBC and multiple newspapers are reporting the Prime Minister will on Thursday appoint a new defence secretary.
Armed Forces Minister James Heappey and Chief Secretary to the Treasury John Glen have both been linked with the role.
The Daily Telegraph also suggested former defence secretary Liam Fox is a possibility.
Dr Fox, who served in the role under prime minister David Cameron between 2010 and 2011, was forced to resign after allowing his friend and best man Adam Werritty to take on an unofficial and undeclared role as his adviser.
The senior Tory MP backed Mr Sunak in last summer’s Conservative leadership race.
Mr Wallace, who served under three prime ministers in his current role, played a key role in the UK’s response to Russia’s invasion of Ukraine and was a close ally of Boris Johnson.
Seen as popular among Tory members, he was at one time seen as a potential leadership contender.
He ruled himself out of the running for the Conservative leadership last year despite being an early frontrunner in the race to replace Mr Johnson.
His successor will take on the high-profile role as the war in Ukraine continues.
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