Australian politics is not as pleasing as it was to Malcolm Turnbull, decrying what he described as an arena that routinely ignores truthfulness but applauds behaviour that encourages dishonesty.

In a speech he delivered in Perth on Wednesday, Mr Turnbull said it was exasperating that the institution he belongs to suffers a deficit of trust, in which spins and exaggerations have emerged as the norm for parliamentary debates.

"It seems to me that we don't simply have a financial deficit . . . we have a deficit of trust," the former Liberal leader was reported by ABC as saying on Thursday.

He was particularly disappointed with how things have unfolded during the Parliament's Question Time over the past two years.

That moment, Mr Turnbull lamented, has become a platform for Prime Minister Julia Gillard and Opposition leader Tony Abbott to joyfully trade barbs, with their respective cohorts all willing to join in the fray.

"For the last two years the questions from the Opposition have been almost entirely focused on people smuggling and the carbon tax. Are they really the only important issues facing Australia?" the former opposition leader asked.

At least when he was at the helm, "there was a concentration of themes when I was leader and Kevin Rudd was prime minister," Mr Turnbull recalled.

The whole picture would have been different had Australia accepted republicanism back in 1999, which today would be possible if the nation will directly elect a president.

But direct election, he clarified, "is no more a silver bullet now than it was in 1999. It's just that it may be the only bullet in the republican arsenal."

The office of the president, when occupied by the right person, "could evolve into a constitutionally functional institution in line with most views of what is needed," making it a suitable alternative to what Australia is made to accept at this time.

What we have at the moment is the deterioration of political discourse with the manner most of the country's political leaders have been behaving, Mr Turnbull said.

Or Australians can demand that their Parliament takes after the British model, he suggested, where majority of the discussions centre on all government portfolios and concerns and not dominated by talks to feed on the egos of party leaders.

"In Britain's House of Commons the prime minister takes questions for half an hour every Wednesday, but on Monday, Tuesday and Thursday Question Time deals by turn with one of the other departments," Mr Turnbull said.

With more pressing issues allowed in the agenda of the Parliament, more trust from the electorate should be given to legislators, he added.

Yet right now, according to Mr Turnbull, the whole system is viewed by many as "nothing more than a forum for abuse, catcalling and spin."