Former prime minister Scott Morrison sought to appoint himself to a sixth secret ministerial portfolio, a report has revealed.
Former High Court judge Virginia Bell's report into Mr Morrison's secret ministries found briefs were prepared for him to be named as agriculture, water and environment minister.
However, Mr Morrison later decided not to go ahead with the decision to appoint himself to the role.
He appointed himself minister to the departments of health, finance, industry, science, energy and resources, treasury and home affairs, without the knowledge of most of the appointed ministers.
But the report said plans were made in April 2021 for a sixth portfolio be added to the mix.
"The prime minister's office also instructed (the Department of Prime Minister and Cabinet) to prepare a brief for (Mr Morrison's) appointment to administer the Department of Agriculture, Water and the Environment," the report said.
"Subsequently, Mr Morrison decided not to proceed with the appointment to administer (the department)."
The report said Mr Morrison's concern in seeking the role related to "powers under the Environment Protection and Biodiversity Conservation Act 1999".
The EPBCA is the central piece of commonwealth environmental legislation, which comes into play when a major project such as a gas project, mine, resort or a pulp mill has the potential to impact heritage, wetlands, threatened species, marine areas and water resources among other matters.
Mr Morrison has admitted to taking on the resources portfolio on April 15, 2021, which he used to veto the PEP11 gas project off the NSW coast, against the wishes of the then minister Keith Pitt.
But until the Bell report was released his interest in the environment role was not publicly known.
A spokeswoman for Mr Morrison told AAP, when asked why the portfolio was sought, "'As made clear in the report, Mr Morrison chose not to request to be authorised to administer that department."
Asked about Mr Morrison's action, Environment Minister Tanya Plibersek told AAP, "I guess I shouldn't be surprised that Scott Morrison wanted to be appointed environment minister too."
"What's important now is ensuring that this can never happen again," she said.
The report, released on Friday, labelled the secret appointments as corrosive of trust in government.
Ms Bell recommended six changes be made following the report, including implementing legislation requiring public notifications of the appointment of minister
She took aim at Mr Morrison's decision not to tell ministers of his appointment to their portfolios.
"It is difficult to reconcile Mr Morrison's choice not to inform his ministers of the appointments out of his wish not to be thought to be second guessing them," the report said.
