Tony Abbott was abused by his chief of staff Peta Credlin at such a volume that her swearing over the phone could be heard by others in his presence, according to a new book.

The Road to Ruin by journalist and former Liberal Party staffer Niki Savva, released on Monday, contains numerous well-documented examples of expletive-laden explosions by Credlin.

Many of the tirades, kept private until now, were excruciatingly embarrassing to witnesses, including staunch Abbott supporters.

• Abbott to Bishop: don’t apologise for chopper
• Tony Abbott ‘used terror threat as political weapon’
• ‘Third piece’ of MH370 show up on La Reunion

On one occasion in the lead-up to the 2013 election, Murray Cranston, one of Abbott’s most devoted advisors, was travelling to the airport in the back of a Commonwealth car with senior press secretary Tony O’Leary. Abbott, in the front seat, was on the phone to Credlin. The conversation got so heated that the two other men could hear her shouting at him to “f*ck off”.

On others occasions, she would yell at Abbott that, without her, he would not have gotten where he was or that he would be nothing without her.

“The truly sad part was that he believed it,” Savva writes.

But, by Monday afternoon, Abbott had hit back at his time in office, saying his government substantially delivered on its commitments.

Abbott said the best response to the book was the objective record of his government.

“The boats were stopped. The carbon tax and the mining tax were repealed. Three free trade agreements that had languished for years were finalised,” he said in a statement.

Mr Abbott said infrastructure got under way under his leadership, including the western Sydney airport that had been talked about for 50 years.

“Our country was kept safe. And a strong start was made to the vital task of budget repair,” he said.

The former prime minister claimed a “dysfunctional opposition” couldn’t win an election and a “dysfunctional government” couldn’t have got so much done in just two years.

“That said, I’m not in the business of raking over old coals nor am I in the business of responding to scurrilous gossip and smear.”

Speaking to The New Daily, Savva revealed that Tony Abbott rang around senior staffers and cabinet ministers asking them not to speak to her. But many of them did.

“This is an important piece of Australian political history, and I think people were keen to have a more complete version of it told,” she said.

As to why so many of the detailed revelations in the book have never been published before, she says: “Previously people were too frightened to speak out.”

Offshore eruptions

Not even being on a sensitive diplomatic mission could curtail Credlin’s behaviour, the book alleges.

On a trip to Indonesia, Credlin and Abbott reportedly had a confrontation at a critical meeting between Australian officials and the Indonesian President Bambang Yudhoyono.

Savva writes that the meeting was to restore the bilateral relationship after a spying scandal and controversy over boat turnbacks. But their dispute quickly escalated. Credlin and Abbott were forced to retreat to an anteroom to argue while numerous Australian and Indonesian officials were kept waiting.

“I remember thinking how indulgent, irresponsible, and arrogant it was to hold everyone hostage to her mood, even on Batam Island in Indonesia,” recalls Jane McMillan, the director of Abbott’s press office during the first year of government.

“It was pitiful to watch.”

Credlin faced intense scrutiny as the chief-of-staff to Tony Abbott. Photo: AAP

Margie marginalised

The most difficult material in The Road to Ruin is the relationship between the former Prime Minister and his wife Margie, whom Savva describes as “a woman of warmth and dignity with the potential to be his greatest asset”.

But Crelin put her in the chiller.

It was this treatment that most bothered staffers. Astonishingly, she insisted that staff at Kirribilli could not order food for Margie or shop for family meals, despite the Abbotts residing at the official residence.

Mrs Abbott may have been prominent during the election campaign, but she soon became the prop of last resort, with her access to the normal assistance offered to a Prime Minister’s wife, including access to his diary, denied.

“He was either oblivious to this or complicit in it,” Savva writes.

“He either simply tolerated it or he incited it. It was one of the biggest single factors in his loss of the prime ministership, wreaking on him the humiliation he feared most: dismissal at the hands of his own colleagues. The fact he could not see it coming, could not see how bizarre his behaviour appeared to others, or what effect it had on their opinion of him and his fitness for the job, was a most worrying aspect of it. It was pitiful to watch.”

According to the book, Ms Credlin not only adjusted her boss’s ties, she shared his desserts in restaurants and fork fed him food off her plate. At the same time she was making life a living hell for almost everyone working in the Prime Minister’s office, ridiculing her co-workers as incompetents.

Savva suggests that Credlin believed Abbott could not govern without her. And as Savva acidly observes, his self-esteem was so low he believed her.

“Even if she had offered to resign, he would not have allowed it. He would have been completely lost, so low was his opinion of his own abilities. Credlin was almost certainly right … Abbott would not have been able continue without her. It was utterly bizarre.”

While the relationship between the pair was apparently toxic, one important question remains. What sort of damage has been done to the Liberal Party by the dethroning of Abbott?

Savva told The New Daily: “Whether any lasting damage is inflicted depends on how serious Abbott is when he says he wants the Turnbull Government to win.”

The Road to Ruin: How Tony Abbott and Peta Credlin destroyed their own government by Niki Savva. Scribe Publications, 336pp. Published today.