Labor has been accused by the opposition of selectively releasing sensitive legal advice when it is in the government's "political interest".
Liberal senator Michaelia Cash asked officials from the attorney-general's department on Wednesday whether they had briefed the government about the release of legal advice on former prime minister Scott Morrison secretly swearing himself into several ministries.
The Albanese government released solicitor-general Stephen Donaghue's advice, which found the ministry appointments undermined responsible government and public faith in political processes.
Labor senator Anthony Chisholm told a Senate estimates hearing there was a lot of public interest in the secret ministries.
"I still get people raising it with me as unusual and symptomatic of our predecessors," he said.
Senator Cash said she was glad he made those comments because it showed "there are circumstances in which a government will release constitutional advice".
"You have confirmed for me that those circumstances clearly include when it is in their political interest to do so," she said.
Senator Chisholm rejected he said that.
Katherine Jones, secretary of the department, said the Commonwealth's standard practice was not to publicly release constitutional advice.
The hearing was also told former attorney-general Christian Porter will not be hired as a lawyer for billionaire Clive Palmer in his $300 billion damages claim against the federal government.
Jesse Clarke, from the attorney-general's department, said Mr Porter had received information about the case while a minister.
"The department checked its records and confirmed that while Mr Porter was attorney-general, he received confidential and privileged information and took decisions regarding the conduct of the dispute," he said.
Mr Clarke said the department sought and received confirmation from Mr Porter that "he has, in fact, not been retained, nor will he act for Mr Palmer, or any of his companies in relation to this dispute, nor has he passed on any confidential information to them".
