Julia Gillard lacked authority as prime minister because of the way she rose to the top job, her predecessor John Howard says.

Mr Howard said she was never able to exercise authority because she was constantly justifying her role in the unseating of Kevin Rudd.

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“The most important thing that a prime minister has is not popularity but authority,” the former prime minister told the Seven Network on Sunday.

Mr Howard described as nonsense Ms Gillard’s famous misogyny speech, in which she lashed out in parliament at the alleged sexism of then opposition leader Tony Abbott.

“The idea that Tony Abbott is anti-women is ridiculous,” he said.

“I think it’s the worst possible way of promoting a greater involvement by women in public life … to play the misogyny card.”

Libs would have lost with Costello

The coalition would have still lost the 2007 election if Peter Costello had replaced him as leader, Howard said in the interview with the Seven Network’s Sunday Night program.

Labor under Kevin Rudd was swept to power in 2007 and Mr Howard, who refused to step aside, lost his seat.

Mr Howard said it would not have mattered if he had relinquished the prime ministership to then treasurer Mr Costello.

“My belief remains that we’d have lost that election whether I had been the leader or Peter had been the leader,” he said.

“So you can argue that it was better that I lose the election rather than someone else, otherwise you’d be taking (out) two leaders for the price of one election.”

In 2010, Mr Costello said Mr Howard had sought to blame everyone but himself for the government’s downfall.

“He appears to be incapable of taking responsibility for the defeat of the government and for losing his seat of Bennelong,” Mr Costello said.

Integration can prevent terrorism

Mr Howard also said a focus on integrating Muslim youths into the mainstream would help prevent them becoming radicalised.

He said that some people had spent too much time in closed communities where such radicalisation could occur.

“As many people know I’m not an overwhelming fan of the doctrine of multiculturalism,” Mr Howard said.

“I believe in bringing people of different races, different religions, to this country but once you’re here you’ve got to become part of the mainstream community.”

Mr Howard said Australia still faced a real threat from terrorism.

“I don’t think any Australian should assume we won’t have a terrorist incident here,” he said.

Mr Howard also said it would not be a good idea to restart a debate about levels of Muslim immigration.

“Apart from anything else, it would be seen amongst friends such as Indonesia and Malaysia as a negative thing,” he said.