GB News' Dehenna has shocked the political sphere by voting against the Prime Minister in tonight's no confidence vote.
The MP for Bishop Auckland, who is part of the 2019 contingent, has previously been an outspoken supporter of Mr Johnson.
But tonight, she posted on social media: “Many of you have understandably asked how I intended to vote in this evening’s confidence ballot in the Prime Minister.
“Though it is a secret ballot, it feels right to share with you how I voted.
“This is not a decision I took lightly. I listened carefully to all sides, and particularly to the many constituents who contacted me sharing their thoughts and experiences.
GB News' Dehenna Davison
Stefan Rousseau
Pressure is mounting on Prime Minister Boris Johnson
Owen Humphreys
"Weighing it all up, I voted against the Prime Minister tonight.
“I hope that, whatever the result, we politicians can now fully focus on the things we were elected to do for you. (And that is why I won’t be commenting further on this now!)”
Mr Johnson’s political future is in the balance as he awaits the result of the confidence vote on his leadership.
Votes are being counted following the secret ballot of the 359 Tory MPs, with the result due at 9pm.
While it would be a major shock if the Tory critics managed to secure the 180 votes required to oust the party leader, his authority would be severely damaged if a significant number of his own MPs have lost confidence in him.
The Prime Minister promised future tax cuts and highlighted his own record of electoral success as he sought to win over wavering MPs.
But with concern over the Partygate scandal, economic policy, drifting opinion polls and Mr Johnson’s style of leadership, the Prime Minister faced a difficult task to persuade his doubters.
The ballot was triggered after at least 54 MPs – 15 percent of the party’s representatives in the Commons – said they had no confidence in the PM.