So the score is Leigh Sales 3, Sarah Ferguson 2. A narrow, but real, victory in the contest about which ABC 7.30 presenter can behave in the most unprofessional manner towards Joe Hockey.

In May last year, Ferguson conducted an aggressive interview with the Treasurer concerning his first budget. The ABC asked former senior Fairfax Media journalist Colleen Ryan to assess the taxpayer-funded public broadcaster’s coverage of last year’s budget. She reported to ABC management in February. Ryan, who is neither conservative nor right-wing, expressed concern about the tone of Ferguson’s interview with Hockey.

Ryan wrote: “The language in Ferguson’s first question was emotive. I also believe that the ­average viewer would consider that the Treasurer was not treated with sufficient respect by the interviewer.”

Ryan also found that two of the Ferguson-Hockey exchanges did “not meet the (ABC’s) impartiality guidelines to treat the interviewee with civility and respect unless there is a compelling reason not to do so”.

As is the ABC’s wont during Mark Scott’s time as managing director and editor-in-chief, the public broadcaster rejected Ryan’s findings. It was announced that “ABC News does not believe Ms Ferguson’s questions were hostile or unbalanced; rather they were astute and prescient”. So there.

Perhaps emboldened by the ABC’s apparent support for the ­interviewers treating Abbott government interviewees without civility or respect, Sales seems to have attempted to out-Ferguson Ferguson, so to speak, in her interview with Hockey on Tuesday night.

Sales seemed to be of the opinion that viewers were as much interested in her views as those of the Treasurer. The 7.30 presenter interrupted Hockey on more than a dozen occasions and took up close to 40 per cent of the interview time.

As with Ferguson last year, Sales’s tone was at times mocking and she failed to treat the Treasurer with civility and respect.

It was much the same later in the evening when Lateline presenter Emma Alberici interviewed Mathias Cormann. She interrupted the Finance Minister on 10 occasions and occupied close to a third of the available time with her comments.

On one occasion, Alberici attempted to close down an issue after accusing Cormann of talking “nonsense”. Here she sounded like a politician in a debate — Hockey, or Labor’s Chris Bowen or the Greens’ Richard Di Natale, perhaps. It’s just that the likes of Hockey, Bowen and Di Natale are expected to be aggressive in stating their positions. That’s not the role of an interviewer.

It is noteworthy that all that came out of the Sales and Alberici interviews last Tuesday was the nature of the interviews themselves. Neither minister said anything of interest because neither was given the opportunity. The reports were all about the aggressive style of Sales or Alberici.

Sales also constantly interrupted Opposition leader Bill Shorten on Thursday night, but her tone was not so disrespectful and she took up less than 30 per cent of the interview time.

Scott remains comfortable and relaxed about the fact the public broadcaster does not employ one conservative presenter, producer or editor on any of its prominent television, radio or online outlets. In public, Scott says this does not matter. In private, the message to the ABC board is that no such conservative talent exists. Both positions are false.

It is true that, when in government, Labor ministers are sometimes treated with a lack of respect by ABC interviewers. It’s just that Labor and the Coalition tend to be criticised by ABC operatives from a green-left perspective.

It is difficult to think of one prominent ABC presenter, producer or editor who opposes same-sex marriage, rejects the alarmism of climate catastrophists or supports the foreign policy positions of, say, George W. Bush, Tony Blair or John Howard.

There are more paid left-of-centre presenters-commentators on Rupert Murdoch’s Fox News than there are right-of-centre paid presenters-commentators on the ABC’s prominent programs. The fashionable leftist orthodoxy prevalent within the ABC affects the tone of ABC presenters.

The likes of Ferguson, Sales and Alberici treat many members of the Abbott government with little respect because this is consistent with the house ethos of the public broadcaster.

The ABC is very much the preserve of the inner-city green Left. That’s why leftist visitors from overseas, who proffer their often ill-informed views on Australia, get such soft treatment on the public broadcaster. A few recent examples illustrate the point.

On March 2, British-born actress Miriam Margolyes was asked a pre-approved question on Q&A — namely “what sort of thoughts” she had about Tony Abbott. She replied: “I think he’s a tit.” This brought much applause from the audience along with laughter from presenter Tony Jones.

But imagine the reaction if, say, Danish-born Bjorn Lomborg called Julia Gillard or Bob Brown “a tit”.

Interviewing Egyptian-born author Mona Eltahawy on Lateline on April 29, Jones said nothing when his interviewee declared that the Prime Minister’s position as minister for women’s affairs was “almost like something out of the Saudi Arabian handbook for ­politics”. In Saudi Arabia, women are not allowed to drive and some are stoned to death for alleged adultery.

Eltahawy went on to assert, without a skerrick of evidence, that “Tony Abbott’s supporters are quite right-wing and often very quick and lazy with their racist assertions” about the Middle East and North Africa.

It’s most unlikely that even the BBC would give a foreigner the opportunity to accuse the likes of Tony Blair and David Cameron of sexism and racism without at least asking for their evidence.

On May 1 Alberici interviewed professor Edward Melhuish at Oxford University’s department of education. She asserted that Social Services Minister Scott Morrison had said that the purpose of childcare in his country was to get people back into the workforce.

Offered the opportunity of a free kick, Melhuish declared: “Well, I’m afraid your minister has a lot of learning to do.” Melhuish has no expertise on childcare in Australia.

The personal treatment of Coalition ministers by ABC journalists, and the tendency of ABC presenters to let ill-informed abuse of Abbott government ministers go to air without challenge, reflects the orthodoxy that prevails within the ABC.

The tone of 7.30 and Lateline presenters is influenced by the fact that the ABC is a Conservative-free zone.