Scott Morrison sought advice on a sixth ministry and did not agree to be interviewed by inquiry

Scott Morrison’s secret appointment to additional ministries was “apt to undermine public confidence in government” and was “corrosive of trust in government”, Virginia Bell has found.

In a report, released on Friday, the former high court justice said Morrison’s appointments to the health and finance ministries were “unnecessary” while three other appointments “had little if any connection to the pandemic”.

Bell found these were an “exorbitant” way to overrule his ministers in the event of disagreement about their use of their powers to cancel visas, approve foreign investment and resources projects – a decision she labelled “bizarre”.

Morrison welcomed the recommendations of the report, insisted he had acted in the national interest and commented that he is “pleased that this matter has now concluded” – despite the fact Anthony Albanese has not ruled out further sanction.

The report reveals that Morrison asked for advice about appointment to a sixth ministry, the department of agriculture, water and the environment, in order to gain powers under the Environment Protection and Biodiversity Conservation Act, but opted not proceed.

Related: Secret ministries: Morrison officials asked industry department for brief on Pep-11 gas project

After the report’s release, Albanese told reporters in Canberra it would “come as a surprise” to Australians who took Morrison’s promise of cooperation at face value that he “did not agree to meet with Bell and communicated only through his lawyers”. He accused Morrison of a “lack of self-awareness”.

Morrison could face censure by parliament when it returns next week, after Albanese repeatedly refused to rule out that option, promising only to consult cabinet colleagues in coming days.

Albanese has previously accused Morrison of misleading parliament, while the deputy prime minister, Richard Marles, has said there should be “severe political consequences” for the member for Cook.

Albanese reiterated that conclusion on Friday, saying Morrison had “misled the parliament, every single day, which he stood there” failing to identify that there were “two people” responsible for the Pep-11 gas project.

Bell said it was “difficult to reconcile” Morrison’s evidence to her inquiry through his lawyers that he believed his appointments would be announced on the government gazette with the fact he failed to tell his ministerial colleagues.

Morrison’s “extremely irregular” arrangements meant there “was no delineation of responsibilities between Mr Morrison and the other minister or ministers appointed to administer the department”, she said.

Bell said the responsibility for the secrecy of the appointments “must reside with Morrison”, but added it was “troubling” the then secretary of his department, Phil Gaetjens, did not take issue with it and argue for disclosure. Bell found criticism of the governor general was “unwarranted”.

Bell made six recommendations to correct the “serious deficiency in governance arrangements” including that in future, appointments and authorisations of acting ministers all be publicly disclosed, including by the prime minister’s department, on the government gazette, and by each department.

In a statement Albanese welcomed the report adding that the “unprecedented and inexcusable actions of the former prime minister were emblematic of the culture of secrecy in which the previous government operated”. He confirmed the government would accept the recommendations.

Related: Scott Morrison warned against further cabinet disclosures in letter from attorney general

In August Albanese launched the Bell inquiry after receiving the solicitor general’s advice that the additional ministry appointments were legal but “fundamentally undermined” responsible government.

Albanese said the Bell inquiry had confirmed that conclusion because Morrison was not “responsible” to the parliament and the people for the departments he was appointed to administer.

Morrison has defended the arrangements as a “necessary” safeguard in “extraordinary circumstances” that were done with the “best of intentions”.

In a statement on Friday afternoon, Morrison said that “at all times as prime minister I sought to exercise my responsibilities in a manner that would best advance and protect Australia’s national interests and the welfare of the Australian people”.

Morrison said the decisions to take on extra powers “were taken during an extremely challenging period, where there was a need for considerable urgency”.

Morrison noted the authorities were valid and were a “dormant redundancy” that was not exercised, except in the case of the PEP-11 decision.

“There is no consistent or well-understood process for publication of the establishment of authorities to administer departments in the government gazette or otherwise.

“No instruction was given by me as prime minister or my office not to publish these arrangements in the government gazette.”

He also defended the manner in which he engaged with the inquiry itself.

“I was pleased to assist the inquiry with six separate and comprehensive responses to matters raised with me and my legal representatives … This engagement was done via correspondence as was the practice with other respondents to the inquiry and accepted by Hon. Virginia Bell.”

On Friday the Sydney Morning Herald reported comments by the former deputy Liberal leader Josh Frydenberg that he did not think there “was any reason” for Morrison to take on the Treasury portfolio.

“The fact he did take it, and it was not made transparent to me and others, was wrong and profoundly disappointing,” he reportedly said. “It was extreme overreach.”

The Liberal leader in the Senate and former finance minister, Simon Birmingham, told Sky News that the early appointments to the health and finance portfolios were “understandable” but “without clarity around the reasons [for the later appointments], it would appear to be overreach, yes.”

But Bell found that even the earliest appointments were unnecessary, because Morrison could have been authorised in a “matter of minutes” to act as health or finance minister, if required.

The appointments are also indirectly under scrutiny in the federal court, where Asset Energy is challenging Morrison’s personal decision to scuttle the Pep-11 permit to explore for gas off the coast of Newcastle.

That case is likely to be removed to the high court now a constitutional argument has been added by the plaintiff.