Tony Abbott is willing to resume the leadership of the Liberal party if his parliamentary colleagues draft him but said he would not run in contested ballot for the top job.

Speaking on Monday evening at an election forum at the Manly Yacht club, where he was questioned by Warringah voters, Abbott made it clear that “notwithstanding the bad polls and the act that we have decapitated ourselves twice, I still think there is a chance of winning”.

A win, in defiance of the polls, would give Scott Morrison an unassailable hold on the leadership of the Liberal party.

I won’t go into a contested ballot Tony Abbott

But if the Liberals lose, the leadership of the opposition will be thrown open.

“I won’t go into a contested ballot,” Abbott said in answer to a question from the audience about whether he would seek the leadership again.

“It will be up to the party room. If they want me they will need to invite me. But I am not expecting that,” he said.

“I am not going to shoulder anyone aside for the top job, because for me it has never been about that,” he said.

In an hour-long session, in which both questions and answers were applauded, Abbott faced questions on on climate change, refugees and his support for Cardinal George Pell, who was convicted of child sex offences late last year.

“I have been a friend of Cardinal Pell for many years,” he said. “He’s been convicted of a horrific crime. Let’s see what happens with the justice system in Victoria. I will be in an awful dilemma if his conviction is upheld on appeal,” he said.

Asked how he justified being a man of faith yet having views so out of step with Pope Francis on climate change and treatment of refugees, Abbott replied that he didn’t regard the pope as infallible on matters of public policy.

He said that in relation to “boat people” there was a duty for the government not to be cruel, but there was also a duty “to defend the interests of our citizens not to have open borders, because it mean we would lose our sovereignty”.

One woman, Leonie, asked about the decline in standards in politics, noting the people in chicken costumes turning up at his rival, independent Zali Steggall’s events, billboards that she described as “misleading and deceptive” and most recently a video which she described as “misogynist and appalling” .

The video which featured a man dressed up as Captain GetUp rubbing himself against an image of Steggall in a sexual manner, was produced by the conservative group Advance Australia, which is supporting Abbott’s campaign. Amid a furore, it was quickly taken down from Twitter.

Abbott said that “of course” he would run an honest and respectful campaign, but he could not vouch for others.

He defended the Liberals’ mobile billboards that say a vote for Steggall is a vote for Labor’s Bill Shorten, arguing that any vote that cut a seat from the Liberal list took Shorten close to the leadership.

He also said that six weeks ago Steggall had said that in the event of a hung parliament she would side with the party that would do more on climate change.

That meant she would support Labor because she wanted a target of a 60% reduction in emissions.

Abbott also strongly criticised the NSW Independent Commission against Corruption and rejected calls for a federal integrity commission.

“The problem with Icac is that it’s very good at destroying people’s reputations. It’s not always that good at getting justice done. I am not going to cry tears over Labor politicians but even one of them seems to have been hardly done by,” he said referring to the successful appeal and an order for a retrial of former mining minister, Ian Macdonald.

“I am very cautious about star chambers and almost unlimited powers to compel evidence,” he said.

Some of Abbott’s answers might have surprised his colleagues and former colleagues as much as they did the audience.

Asked if he was going “to continue to be a wrecker” and why he had voted for Peter Dutton in last year’s leadership spill, Abbott said that if he was a wrecker he would have left parliament and created a by-election.

“Instead I sat quietly on the backbench and campaigned for the re-election of the Turnbull government,” he said to guffaws.

“When I won the leadership I put Turnbull into cabinet. He didn’t return the compliment,” he said.

“I said, that’s fair enough, that’s your call, but you have to understand I have some pretty strong views on policy and as long as I am on the back bench I will speak my mind because that’s what backbenchers are entitled to do,” he said.

As for Peter Dutton, Abbott said he had voted for him “only after Turnbull had vacated the position”. As much as he admired Dutton, the party had a better chance of winning under Morrison and had made the right choice, he said.

“Until Malcolm Turnbull put his position into play last year, I didn’t want to change leader either,” he said.