Former prime minister John Howard has intervened in the ongoing conflict within the government by telling disgruntled Liberals to united behind Turnbull and accept that the leadership question is settled.

The party elder told Sky News on Thursday night that his party needed to “stop raking over old coals” — a comment that will be interpreted as a warning to Mr Abbott.

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“They clearly voted in a new leader,” Mr Howard told Sky News.

“They are not going to reverse their position and people now in my view have to, hard though it may be for some, have to stop raking over old coals and focus on the main game. And the main game is making sure that the Coalition is re-elected.”

Almost immediately after losing the prime ministership in September 2015 and for months since, Abbott has made regular public comments that contradict or undermine new leader Malcolm Turnbull. Many analysts have compared this to the Labor party ‘wrecking’ perpetrated by Kevin Rudd against Julia Gillard.

Mr Howard revealed in the interview that he advised Abbott to sack then-treasurer Joe Hockey and chief of staff Peta Credlin.

Interestingly, Abbott used the same coal-raking reference when he refused to comment on claims he had an affair with Ms Credlin. The rumour was reported in a new book by journalist Niki Savva.

“I feel for Tony, because it was very humiliating and he had won an election,” Mr Howard said. “But the people who have the authority to make the decision, made the decision.”