Alan Tudge (Image: AAP/Lukas Coch)

When does private behaviour become a matter of public interest? 

And after last night’s Four Corners expose, are we about to see an explosion of stories about politicians — from both sides of the aisle — behaving badly? 

Four Corners attempted several public interest justifications, including workplace standards and the rationale that Christian Porter, as first law officer, needs to be held to the highest standards (though a cursory look at his political performance would bring him undone on that score).

But perhaps the program’s strongest argument is that of hypocrisy.

Sign up for a FREE 21-day trial and get Crikey straight to your inbox

By submitting this form you are agreeing to Crikey's Terms and Conditions.

There was Alan Tudge, standing up for traditional marriage while having an extra-marital affair with a Liberal staff member. There were election campaigning images of Porter the Perth family man who happened to — allegedly — have a whole other life going on in Canberra.

The same argument raged 30 years ago when 60 Minutes covered then Liberal leader John Hewson by interviewing his first wife and the mother of their three children, who Hewson had left.

Despite lobbying from Hewson, Nine’s then owner, Kerry Packer, agreed to the program going to air on the grounds that it exposed the hypocrisy of the white-picket-fence family man image Hewson was using for his political marketing.

The Hewson episode did not unleash tit-for-tat political leaking, even though there was plenty of available raw material.

What has emerged about the insider goings-on of Canberra has nearly always come via the outsider media.

In December 2018, New Idea exposed the sugar daddy exploits of then National Party MP Andrew Broad who used taxpayers’ money to partially fund a trip to Hong Kong, where he planned to meet a woman he had contacted via an online dating site. Nationals leader Michael McCormack had reportedly known the facts of that matter for two weeks before it was exposed.

In late February 2018, then Daily Telegraph journalist Sharri Markson revealed that National Party leader Barnaby Joyce and his former staffer Vikki Campion were expecting a baby together. Joyce, like Tudge, had been an opponent of same-sex marriage. Joyce went on to hold his seat comfortably in 2019.

At the end of 2019, Queensland National Party MP George Christensen — another morals campaigner — was revealed to have been a regular visitor to Philippines sex bars. Christensen paid back any public money he had spent on flights, looked to the backing of colleagues in the LNP and saw his vote increase markedly at the subsequent 2019 election. 

Despite former prime minister Malcolm Turnbull’s insistence on moral rectitude, there are powerful disincentives for politicians to rat on each other. Apart from the glass houses argument, it appears there is no consequence at the ballot box.

Ultimately, of course, hypocrisy is one of the glues that holds politics together. And when it comes to the sex lives of politicicans, it’s all controlled by a cosy Labor-Coalition duopoly.

If the Four Corners bombshell changes the ground rules of private lives in politics, and both sides start raking muck, it will need to be a bi-partisan deal.