Robert Jenrick's media plan for his defection to Reform reportedly refers to him as "the new sheriff in town" and "the biggest defection story" Nigel Farage's party has ever had.
The leaked plan references the defection of the former Tory chancellor Nadhim Zahawi on Monday, signalling that it was prepared in recent days.
Jenrick has conceded that he was "resolved" to switch to Reform before Kemi Badenoch fired him.
The Tory leader dismissed Jenrick as shadow justice secretary and suspended him from her party on Thursday, accusing him of plotting to jump ship.
She is thought to have launched her pre-emptive action after a draft of Jenrick's resignation speech and this memo were passed on to her team.
It refers to the Newark MP as the "the biggest defection story Reform has ever had" and the "new sheriff in town", the Mail on Sunday and the Sunday Times reported.
Jenrick appears to have underlined the words "here to support Nigel".
A source close to Jenrick said he had no involvement in the drafting of the document.
A spokesperson for Jenrick said: "As the document makes clear, Rob is just a member of Nigel's team and wants to help get him in as prime minister.
"And it's a team which, unlike the Tories, wants to change Britain rather than pretend it isn't broken."
Jenrick has continued his attacks on his former party.
The Newark MP told the Sun on Sunday: "It's almost become the party of posh people.
"They are so out of touch with the people I grew up around in Wolverhampton and represent in north Nottinghamshire."
He added: "The divide in British politics has become Reform's workers' party versus the Tory posh party."
Badenoch meanwhile said her former frontbencher was a rightwing "pastiche".
"I know what I believe. I know what I stand for. Robert has a pastiche of what he thinks the right wing is, and then he performs towards it. It's always been about his personal ambition," she told the Telegraph.
The opposition leader has ruled out any future rightwing pact with Reform.
Jenrick has said his move to Farage's party was "uniting the right".
Badenoch said the right was "not a single, homogenous bloc".
She said: "Many people on the right actively dislike Reform. Trying to 'unite' risks losing just as many voters as it gains.
"Reform isn't interested in fixing the country; they're interested in disruption. We are not offering the same thing, and I don't want voters to think we are."
Reform has said 7 May will be a cut-off point for admitting Conservative defectors.
Farage said this would be "deadline day" for current and former MPs as well as local councillors to defect.
"Those who join must be resolute in their conviction that the established political parties have broken Britain," he wrote in the Telegraph.
He said: "It is make your mind up time, and if that sounds like an ultimatum, it is."
Asked if she would be on high alert for MPs potentially seeking to switch sides before 7 May, which is when crucial local elections take place, Badenoch said: "I think people should be wondering why they set that deadline.
"Perhaps they're worried that they're not going to get anyone any more.
"But to be honest, this is a distraction from the serious things that are happening in the country right now.
"Reform love talking about defections and themselves and polls. We're talking about the country and what matters to you."
She told broadcasters it had been an "interesting week" and signalled she was willing to clear out disloyal Conservatives from the party.