A new book has exposed the deep dysfunction at the heart of the Abbott government and revealed the former prime minister was warned he should dump his chief of staff Peta Credlin, partly because of a “perception” they were having an affair.

Senior government figures have come forward to give on-the-record accounts of their attempts to convince Mr Abbott to sack Ms Credlin, in order to avoid being ousted himself.

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Book says Concetta Fierravanti-Wells approached Abbott and Credlin about rumours. AAP

At one point, senior Coalition figure Senator Concetta Fierravanti-Wells is quoted as confronting Mr Abbott and Ms Credlin about rumours circulating among their colleagues that he was “sleeping with” her. Both denied it.

The accounts are published in a book by Niki Savva called The Road to Ruin: How Tony Abbott and Peta Credlin destroyed their own government.

It focuses on the insular relationship between the pair, and the influence and power Ms Credlin had within Mr Abbott’s office.

According to an extract published in The Australian, Senator Fierravanti-Wells went to Mr Abbott the night before the failed first attempt to unseat him last February.

She told the then-prime minister he had to remove Ms Credlin, arguing colleagues considered her responsible for many of the government’s problems, and they were prepared to take out their frustrations on him.

Senator Fierravanti-Wells is quoted in the book as telling Mr Abbott “politics is about perceptions”.

“Rightly or wrongly, the perception is that you are sleeping with your chief of staff. That’s the perception, and you need to deal with it.

“I am here because I care about you, and I care about your family, and I feel I need to tell you the truth, the brutal truth. This is what your colleagues really think.”

According to the book, Mr Abbott responded calmly and said the rumours were not true.

Mr Abbott was not ousted in that February ballot, but the chain of events was considered a precursor to his ultimate downfall in September.

According to the book, Senator Fierravanti-Wells also put the rumours directly to Ms Credlin a few days after the February ballot.

Ms Credlin also denied it, and the recollection is that she said she would not leave Mr Abbott’s office, arguing he would not be able to do his job as prime minister without her.

“One day, Tony will be sitting on a park bench in Manly feeding the pigeons, and he will blame you,” Senator Fierravanti-Wells replied, according to the book.

Channel Nine senior political journalist Laurie Oakes has also had access to the book ahead of its publication on Monday, and said Ms Credlin’s comment showed she thought Mr Abbott was incapable of doing his job without her.

Credlin believed Tony Abbott could not do his job as prime minister without her. (AAP: Penny Bradfield)

According to Mr Oakes, the book includes a quote — with the approval of a senior government adviser — that says: “He [Abbott] knew he wasn’t up to it, she knew he wasn’t up to it, so they both hunkered down.”

Mr Oakes has written about another anecdote from the book provided by a Liberal MP.

The MP recalled being invited to dine with Mr Abbott and Ms Credlin and watched Ms Credlin use her fork to feed Mr Abbott mouthfuls of food from her plate.

As the meal was ending the MP recalled Ms Credlin put her head on Mr Abbott’s shoulder and said she was tired.