A number of Conservative MPs in Norfolk and Waveney face a stark choice as Michael Gove was knocked out of the race to be prime minister by just two votes.
Waveney MP Peter Aldous and South Norfolk MP Richard Bacon had backed Mr Gove in the contest, so would now have to choose whether to support Boris Johnson or Jeremy Hunt in the final stretch.
While Keith Simpson, MP for Broadland, had previously declared for Jeremy Hunt, and continued his support as he warned: "My message at the end of the day is Boris will let you down."
North West Norfolk MP Sir Henry Bellingham previously backed Dominic Raab and Mid Norfolk's George Freeman backed Matt Hancock - both of whom left the contest earlier.
While South West Norfolk MP Liz Truss and Norwich North MP Chloe Smith had already declared their support for Boris Johnson.
Brandon Lewis, Great Yarmouth MP, has to remain neutral as party chairman.
Sir Henry said he was now backing Mr Johnson, who he said would "stop traffic" if he visited Norwich or King's Lynn.
He said: "I will be supporting Boris and I'm encouraging my members to vote for him. It's a very tough time, we almost got wiped out in the European elections and in every constituency we've got the threat of the Brexit Party. We've got to have someone who is absolutely determined to take us out.
"I think at a time of crisis, where we've slipped behind the Brexit Party in the opinion polls, it's slightly scary if you're a Conservative at the moment unless we get a grip of something and come out of the EU. I think the one person who will most likely to put Farage out of business is Boris."
Mr Aldous was yet to decide who he would back but said he was disappointed by Mr Gove's defeat.
He said: "I believe he had an exciting vision for the UK and a pragmatic plan for delivering Brexit."
Mr Simpson, who was the only Norfolk Tory to have declared for Mr Hunt at the time of writing, said: "Boris Johnson has been ahead and has half of the parliamentary party declaring for and voting for him, but he's got half of the party who are not. I would never vote for Boris Johnson and understandably his team never contacted me. My message at the end of the day is Boris will let you down."
He added: "Jeremy Hunt was a very successful business man, he's been a very successful Cabinet member."
Ms Truss, who is the bookies favourite to be chancellor if Mr Johnson wins, tweeted: "Great result for @BorisJohnson, getting the support of more than half of Tory MPs. Looking forward to the final part of the race. #BringItOn"
The whole Tory Party membership will now vote for their preferred leader, after a hustings tour of the country, with the result expected by July 22.
- More to follow.
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