The AAT has returned to the department of prime minister and cabinet’s case after hearing Rex Patrick’s submissions about the status of national cabinet this morning.

Justice White has started the afternoon session with a challenge to the department: where in the evidence is there proof that it was a decision of the prime minister to set up the national cabinet?

Counsel for the department, Andrew Berger, said:

It was established by agreement of the prime minister, premiers and chief ministers. Although it was a collective decision to establish it, the power or authority stemmed from the prime minister. If the PM hadn’t have agreed, it couldn’t have been established.

Berger said it is “beside the point” whether Scott Morrison set it up individually or collectively in consultation with others.

Earlier, justice White asked whether the affidavit of Phil Gaetjens, the departmental secretary, states whether he was present at the Council of Australian Governments meeting setting up national cabinet.

The answer was: no, it doesn’t say.

The Rule of Law Education Centre is running an event titled the Presumption of Guilt, a conference that promises to “examine recent challenges to this doctrine and the threat this poses to the Australian concept of a ‘fair go’”.

The centre has billed Christian Porter, the industry and science minister, as one of the guest speakers.

That would be quite a get for the conference – both because of Porter’s experience as the former attorney general and his personal circumstances.

Porter has been accused of sexually assaulting a 16 year old when he was 17 in 1988. He emphatically denies the allegation, and is suing the ABC for the article first revealing the claims against an unnamed cabinet minister.

But a spokesman for Porter told Guardian Australia that Porter “hadn’t actually accepted” an invitation and will not speak at the event. Asked why he had been advertised as speaking, the spokesman replied that organisers may have been “getting ahead of themselves”.

Guardian Australia has contacted the Rule of Law Education Centre for response.

The prime minister, Scott Morrison, has said Porter is entitled to the presumption of innocence, because NSW police closed their investigation when the alleged victim withdrew from it before taking her life. Porter is an “innocent man under our law”, Morrison has said.

Reflections on the presumption of innocence will be left to the other guest speakers. According to the centre, they are Ron Hoenig MP, Margaret Cunneen SC, Malcolm Stewart and Chris Merritt.