The Northern Territory's Chief Minister Terry Mills has reportedly been replaced by Transport Minister Adam Giles.
Party insiders have told the NT News there has been a "substantial swing" in the numbers.
Mr Giles is expected to hold a press conference later on Wednesday.
According to Sky News, the CLP partyroom voted 11-15 to roll Mr Mills, who is in Japan and was told by phone.
Only last week Mr Mills admitted that Mr Giles had challenged him for the leadership at a marathon meeting of CLP MPs.
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"There was a change in direction for a time where there was a discussion over a tilt at the chief minister's position," Mr Mills said at the time.
"The room resolved, and I can report to you, that that was not acceptable and then we turned back to the matter at hand."
Indigenous Advancement Minister Alison Anderson said later that the CLP had been "bleeding" during the meeting, which involved hours of infighting.
She told AAP Mr Giles could have been the NT's first Aboriginal treasurer and deputy chief minister but he threw that back in the face of his colleagues.
"He said, 'I don't accept it because I want to be the chief minister,' and he just threw a spanner in the works," she said.
"We sat there for hours while this infighting was happening and the party bleeding everywhere."
Other details of the meeting were also leaked to reporters including threats from four MPs in bush seats to sit in the parliament as independents if Mr Giles took the leadership.
