A DOWNING Street operation to stifle a challenge to Boris Johnson’s leadership is in the works as the number of Tory MPs pulling their support for the Prime Minister continues to rise.

A UK minister told PoliticsHome a “huge save Boris operation” had kicked off on Tuesday afternoon as a response to the number of Tory MPs publicly calling for his resignation reaching at least 30.

A senior Government source said that Johnson was still the Tory party’s strongest electoral asset, despite Labour leading in opinion polls.

"Where is the genuine alternative?" they asked. 

In a bid to safeguard support for the Prime Minister, Tory whips have been phoning Conservative MPs to deter them from sending letters of no confidence to Sir Graham Brady, chair of the 1922 committee.

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And according to reports, the Prime Minister has been personally phoning MPs as well.

A Government source suggested there is “an increased wind of change this week” within the party after last week’s reaction to the Sue Gray report was initially muted.

One Tory MP elected in 2019 has said that a leadership vote "feels inevitable now".

They added that the threat was particularly dangerous because the dissenting MPs are “dotted all over the country” and not confined to a particular section of the party.

Adding to the air of uncertainty, on Tuesday, Science Minister George Freeman refused to say whether he thought Johnson would face a vote of no confidence.

"I don't know where backbench colleagues are," he said.

Freeman was also unsure of whether the Prime Minister could win a leadership vote.

"Honestly you'd have to spend as much time as you do talking to my colleagues to know the answer to that. I just don't know," he added.

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Giving a clearer image of how widespread the discontent is amongst the sub-factions of the Tory party, the Telegraph has published a breakdown of the 30 Tory MPs calling for Johnson’s resignation.

Their analysis shows that the rebels are split on Brexit, with 17 of the 30 being pro-Leave and 13 in the Remain camp. Adding to the diversity of the group, every intake of MPs over the last 40 years except for 2017, is represented among the rebel MPs.