Before the book was for sale, Abbott had dismissed it as "scurrilous gossip and smear". Credlin called her a "so-called journalist". Critics were using her marriage - to veteran Liberal Party staffer and current Turnbull staffer Vincent Woolcock - to question Savva's independence. Niki Savva, author of the book Road to Ruin. Credit:Alex Ellinghausen Paul Keating had done the same many years ago when she was critical of his prime ministership, bagging her as a "Tory bitch". During the Rudd-Gillard years, Savva recalls: "I was the darling of the conservatives; they all thought I was wonderful because I was getting stuck into the Labor Party. "Abbott would text reasonably frequently to say, 'Good column, very shrewd observations'."

But as her columns in The Australian became increasingly critical, she says she transformed into the "she-devil" of the Abbott government. Niki Savva with current speaker Tony Smith and other former advisers to prime minister John Howard in 2001. "Even those of us who thought we were insiders learnt something reading her column," says one of the key players in the Turnbull coup. "A few times I remember reading it and thinking, Holy shit, I didn't know that." Tony Abbott and former chief-of-staff Peta Credlin asked Savva's former editor to sack her. Credit:Alex Ellinghausen

The MP notes that after running The Age and Herald Sun Canberra bureaus, she worked for Peter Costello and John Howard: "She knows what makes the Liberal Party tick; she knew what would get under the skin of a Liberal Party MP better than anyone else in the gallery." Credlin and Abbott loathed her columns so much they told The Australian's editor-in-chief, Chris Mitchell, to sack her. Mitchell refused, saying no prime minister or chief of staff had ever demanded such a thing. Alarm bells about the Abbott operation started ringing for Savva when they were still in opposition, after Liberal staffers told her his office was "constipated" because nothing could get past Credlin. Still in touch with many fellow operatives from the Howard years, Savva became a magnet for those with unflattering tales about Abbott and Credlin. Someone even sent her photos of the pair holidaying in France.

"The more I wrote, the more people would come to me with information," she says. "Day-to-day journalists have to maintain contacts and that means they ignore things that sometimes they shouldn't. "I have nothing to lose. I don't have a long career ahead of me I'm trying to preserve." Controversially, Savva didn't approach Abbott or Credlin to comment for her book - despite detailing rumours of an affair between them. She also didn't speak to staffers with a more flattering view of the pair. This has made it easy for critics to argue she wrote her account with a pre-determined agenda. "My view was: why should I peddle their lies?" Savva says.

"I knew from bitter experience that you could not trust their version of events." Veteran journalist and former colleague Laurie Oakes, who describes Savva as "gutsy", says it would have been "pointless" to ask them to participate. "I would check things with Abbott's office and be misled," he says. "One press officer even boasted openly about fooling members of the press gallery." Although she has only met Credlin a handful of times, there's no doubt Savva's dislike of her is deep and personal. "She had carried on like this for years - bullying people, abusing people - but no one could say anything because they didn't want to lose their jobs.

"Some of them used to be her friends, used to admire her. I know these people; I trust their versions of events." Savva knows how tough politics and journalism can be. When she was a reporter, a Labor MP spread rumours claiming she was getting her stories through an affair with a fellow politician. She and Peter Costello didn't speak for eight years after she published a book about her time working as his press secretary. "I don't care how much they attack me," she says of Credlin and Abbott. But she says dragging her husband into it is "pathetic", noting that he has worked for every Liberal leader since Billy Snedden including Abbott. She insists she will subject Turnbull's prime ministership to the same scrutiny as Abbott's. "You'd look stupid, you would sacrifice your own credibility otherwise. I will call it as I see it."