Getting to the truth, in the public interest, is a tough job when you're interviewing a politician whose mission is to stick to the script. Being politely aggressive is often the only option, writes Monica Attard.

Kerry O'Brien isn't the first person to claim that political interviewing has become gladiatorial. In fact, it's probably the most unoriginal insult to have been hurled at those who engage in that art.

"I think some people regard gladiatorial interviewing as good interviewing, and I never did," O'Brien told ABC's Home Delivery.

"It's the nature of political interviewing now, certainly with those so-called 'gotcha moments'. I never really consciously went for gotcha moments, but when you did occasionally get one it was, I thought, for the right reasons."

Who but the journalist him or herself can ever speak to motive in going for the gotcha moment?

But if it is the nature of political interviewing to seek to reach beyond what the politician wants to say, then in the course of a legitimate and respectful line of questioning, a gotcha moment is the exact result we should expect.

Lest we forget O'Brien's extraordinary interview with then opposition leader Tony Abbott, who ended up admitting not everything he says is true.

Or Leigh Sales' interview with Mr Abbott, who claimed BHP had suspended a project because of the carbon and mining taxes, not having read the company's actual stated reasons.

In the years I watched O'Brien present Lateline and then 7.30, I would have labelled him the king of the exacting political interview where you might almost hear bets being laid in the green room as to who was going to come off better - KOB or the poor politician in his sights.

And that's a compliment by the way, for who else but a loved and trusted interrogator could or even should bring to heel the politician, generally though not always, pulling one over us? To do so politely and intelligently is a bonus for the viewer.

But there's a bigger issue to prosecute - that gladiatorial interviews are now "in the nature of political interviewing".

Have Australian journalists sacrificed us, whom they represent (or at least should), to the entertainment and sometimes commercial demand for a good old barney with some hapless member of the political class?

Political interviewers like Sarah Ferguson are a bit like courtroom prosecutors. ( The Killing Season )

Survey the Australian media circa 2016 and the answer is probably "no", with some exceptions.

An interviewer isn't a reporter. A reporter reports facts, unsullied by opinion and interpretation. The interviewer's role is to take facts and interpret them as the public might interpret them, and then test them.

It's by definition an interpretative exercise. The very best political interviewers - amongst whom I would class Leigh Sales, Tony Jones, Sarah Ferguson and David Speers - are a bit like courtroom prosecutors. Their role is to place the subject on the stand and get them to tell the truth by placing on the table their interpretation of what's been presented as fact and testing its veracity.

It is by its very nature adversarial because politicians and journalists are not and shouldn't be on the same side. And like most court room encounters, sometimes it can get a little dramatic. If it looks gladiatorial, it's because the political process is pit against the journalistic demand for accountability.

It's balancing the dramatic moments with the search for the truth, or the all-important moment of political accountability, that gets tricky. And sometimes the balance is lost.

What upsets a lot of people is when that balance gets lost for obvious commercial and/or entertainment reasons, when the interrogator loses authority to speak for the viewer or listener (and in the public interest) because they are so clearly acting in someone else's interest.

Commercial radio is bursting at the seams with shock jock interviewers who think it their duty to rudely tear apart politicians and, in so doing, make a fleeting headline on the Sydney Morning Herald website's front page.

It's good for business with the dubious advantage that it keeps their audience believing the host is on their side, acting in their interest. But few political observers take these encounters all that seriously, unless they produce some evidence of political hypocrisy. They see it for what it is, crass and commercial.

But I'm struggling to think of any examples of this at the ABC or indeed Sky, a commercial outlet.

It was ever thus that politicians try to - and often succeed at - sticking to the script. There's a message, updated daily, and their job is to ensure they and others don't stray from it in the interests of the party to which they belong. Little of that has much to do with the public interest.

Getting to the truth, in the public interest, can be - usually is - a tough job in these circumstances. In fact, being politely aggressive is often the only option, in the public interest. Nothing gladiatorial about that. It's not a contest aimed at producing a winner. It's a contest aimed at producing some truth, just as O'Brien's most memorable political interviews did.

Perhaps the perception that political interviews are gladiatorial by nature is being fed by a hyper competitive media in a landscape overflowing with news outlets, that feeds on otherwise insignificant encounters between political interviewers and politicians.

The latest that comes to mind is the headline that shrieked "Leigh Sales shuts down Malcolm Turnbull in ABC 7.30 interview".

The new Prime Minister was trying to do what politicians do - change the conversation. Sales called him out. If she hadn't, could she legitimately call herself a political interviewer?

I doubt it.

Monica Attard is a Walkley Award-winning journalist and a former broadcaster at the ABC. Follow her @AttardMon.