"My responsibility as Prime Minister of the country of which I am proud, was to have stepped into the breach and made that difference," he told viewers of the ABC's Q&A on Monday night.

"On top of that, to take the pretty breathtaking decision when it was presented to me of signing off a guarantee for every single person's bank deposit in this country when the financial crisis was at its worst. When banks were falling over around the world and people losing their deposits, we had to step in, make a decision so each one of your savings deposits was looked after."

Mr Rudd faced an at times hostile crowd of questioners, who grilled him on a diverse range of issues as including cost-of-living pressures for earners on the top tax bracket, the "abnormality" of homosexuality and nurse-to-staff ratios for aged care nurses.

A young woman left Mr Rudd looking slightly stunned when she told him that, "You and Tony Abbott to me seem almost the same person."

Another audience member left him momentarily lost for words when he asked the Prime Minister: "Kevin, besides the weather vane of public opinion, what do you actually stand for?"

Mr Rudd earned his most enthusiastic applause when he faced down a preacher who questioned why Mr Rudd, as a Christian, supported same-sex marriage and didn't "believe the words of Jesus in the Bible".

"The Bible also says that slavery is a natural condition," Mr Rudd shot back.

"If you think homosexuality is an unnatural condition, then frankly I cannot agree with you based on any element of the science. If a person's sexuality is as they are made, you have to ask the second question - should, therefore, their loving relationships be legally recognised and the conclusion I have reached is they should."

Mr Rudd also won a warm reaction when he told the audience that if Labor were re-elected one of his first acts would be to repeal the government’s changes to parenting payments.

Last year the then-Gillard government announced it would move some 65,000 single parents, mostly women, from the Parenting Payment to the dole when their children turned eight. Some lost $150 a fortnight.

"If we are returned, it will be the first thing we address," Mr Rudd said.

"I mean it. I am not comfortable with where we are on this. As soon as the budget opens up that amount of space to deal with this challenge, we should act."

Asked whether the policy change was in line with Labor Party values, Mr Rudd said:

"I was very uncomfortable with it then. I am very uncomfortable with where we are now. I am being up-front about it. As soon as the budget allows us a bit of space to act on that, we will."