Australian politics is right back in the sewer. Prime Minister Scott Morrison’s defence of Energy Minister Angus Taylor, who is the subject of an investigation by NSW Police, and his own questionable phone call to NSW Police Commissioner Mick Fuller, today led to a toxic tit for tat that even dredged up ancient allegations against former Labor leaders Bill Shorten and Julia Gillard. It was impossible to watch Question Time today without losing respect for the parliament, as an institution, and just about everyone in it.

The day began with debate about the prime minister’s decision to call Commissioner Fuller about the investigation into whether any crimes were committed when Taylor’s office provided a doctored copy of the City of Sydney’s annual report to The Daily Telegraph. Former prime minister Malcolm Turnbull kicked that along in an interview with Sky News Australia, saying: “It would have been much better if [that call] had not been made, because it is … vitally important that that inquiry that is being conducted by the NSW police – like every inquiry they undertake – is seen to be conducted entirely free of political influence. Being blunt about it, it is a call I would not have made.”

Fuller, who lives in Morrison’s electorate, has previously joked in an interview with 2GB’s Ben Fordham that he was a mate of the PM, saying that Morrison used to bring his bins in on rubbish night. He later gave his own media conference, declaring that the bit about the rubbish bins was a joke, and saying that in their short call yesterday “the prime minister … didn’t ask for anything that was inappropriate and I’m comfortable with the discussion that we had over a few minutes.”

Just about every question Labor leader Anthony Albanese asked today was directed to the prime minister, underlining that this whole affair is no longer about the integrity of Angus Taylor but the integrity of Scott Morrison. Morrison dug in, explaining: “The purpose of my call was to fulfil my undertaking to the House and discharge my responsibility under the statement of Ministerial Standards to inform myself of the nature, substance and instigation of the investigation under way.” That prompted a flurry of new questions, because it suggests a more substantive conversation than Fuller may have let on.

Morrison dug in deeper, saying: “[Fuller] said, ‘To be honest with you, these types of investigations can consume an enormous amount of resources from NSW Police and they are a great diverter of my time.’” It sounded pretty chummy. That impression was deepened by another rhetorical flourish from the PM, who at one point shouted at Albanese: “He’s the one who comes into this place with trumped-up claims, because at the end of the day, he’s got nothing.” Along the way the PM threw dirt back at Labor, harking back to police investigations into Shorten and Gillard, which both came to nothing. Ultimately the government resorted to gagging debate, just like yesterday, except this time it was to defend the PM. In all this, it’s the public that’s left gagging.

Whatever the fate of Taylor – and Sky News Australia host Laura Jayes tipped that he was likely to be the Morrison government’s “first scalp” – the political system is the loser. The most important question, briefly popping the Canberra bubble, was from independent MP Zali Steggall, who said: “Trust in politicians is at an all-time low, and it is dipping day by day. It is our responsibility to fix it. Parliament is paralysed by these allegations that need to be investigated by an independent body. Could you inform the House when the government’s bill on a national integrity commission be introduced, and will it include powers to investigate parliamentarians and their staff?” Murmurs of that being a good question echoed around the halls. There was no good answer.

The government’s catchphrase all week has been stability and certainty, but the only certainty is that today’s new low standard for ministerial responsibility will be matched and exceeded in the future. It’s difficult to watch our representatives laughing at their own jokes while failing to meet basic standards of decency and accountability. The only person who didn’t appear entertained by today’s hilarious proceedings was Angus Taylor, who sat po-faced throughout Question Time, as though he was in the naughty corner.