Julia Gillard was a disloyal deputy involved in the conspiracy to take down Kevin Rudd as prime minister, says former Labor MP Maxine McKew.
In her new book, Ms McKew says Ms Gillard directly undermined Mr Rudd in the days before she ousted him in a coup, Fairfax reports.
Ms Gillard has always maintained she was loyal to the then prime minister until the day she challenged him.
But Ms McKew writes Ms Gillard showed internal Labor research critical of Mr Rudd to a senior member of the caucus in the days before the challenge.
This unnamed Labor member believed his encounter with Ms Gillard was part of the conspiracy against Mr Rudd, Ms McKew says in the book.
Ms McKew's book, Tales from the Political Trenches, will be published on Monday.