Outgoing Liberal senator Concetta Fierravanti-Wells has taken aim at Prime Minister Scott Morrison, describing him as "an autocrat" and "a bully with no moral compass" who pretends to be a man of faith.
The conservative senator from New South Wales will leave politics at the next election after being placed in an unwinnable position on the party's Senate ticket.
In a speech to the Senate on budget night, Senator Fierravanti-Wells accused Mr Morrison and Immigration Minister Alex Hawke, a factional ally, of corrupting the party's New South Wales division.
"There is a very appropriate saying here, the fish stinks from the head," she said.
"Morrison and Hawke have ruined the Liberal Party in New South Wales by trampling its constitution."
Senator Fierravanti-Wells described her demotion in preselection as "dodgy" and accused Mr Morrison of having a hand in various political manoeuvres within the party over decades.
She said she had received thousands of emails from angry members in recent months who had "lost faith" in the party.
"They don't like Morrison and they don't trust him," she said.
"They continue to despair at our prospects at the next federal election."
The outspoken right-wing senator said Mr Morrison had "honed his manipulative skills" during his time as state director of the party's NSW division.
"He is adept at running with the foxes and hunting with the hounds, lacking the moral compass and having no conscience," she said.
"His actions conflict with his portrayal as a man of faith.
Last week the federal executive of the Liberal Party took over the preselection of candidates in numerous NSW seats, denying rank-and-file members a chance to vote for their preferred candidates ahead of the upcoming election.
The move gave Mr Morrison and NSW Premier Dominic Perrottet the power to hand-pick candidates for key federal seats, including Parramatta and Hughes.
Referencing the matter, Senator Fierravanti-Wells claimed Mr Morrison and Mr Hawke had deliberately contrived a crisis in the NSW division to justify installing their own preferred candidates.
"There is a putrid stench of corruption emanating from the New South Wales division of the Liberal Party," she said.
"Hawke as his representative on state executive for months and months failed to attend nomination review committee meetings to review candidates, thereby holding up preselections."
"Spurious arguments were mounted to justify the unjustifiable. The constitution was trashed."
The ABC has contacted the Prime Minister's Office and the office of Mr Hawke for comment.
