Australia’s second-highest law officer has quit his job saying his relationship with Attorney-General George Brandis had been irretrievably broken.

Solicitor-General Justin Gleeson and the attorney have been embroiled in a public spat over changes to Mr Gleeson’s role, principally that no one including the Prime Minister could seek the Solicitor-General’s advice without the attorney’s permission.

Mr Gleeson said while he regretted having to take the decision, it was the necessary step to resolve the impasse between them.

“The best interests of the Commonwealth can be served only when its first and second law officers enjoy each others’ complete trust and confidence within a mutually respectful relationship.

“When such a relationship is irretrievably broken, as is the case here … there must be some resolution to the impasse.”

Earlier this month, Mr Gleeson told a Senate inquiry the “radical change” to his role was unlawful and threatened his independence.

Mr Gleeson said he had not seen the new direction until May 4, after it was issued by Senator Brandis, and that he had asked the attorney to withdraw the order and engage in proper consultation.

Senator Brandis has rejected claims he was undermining the Solicitor-General, and that the directive amounted to a power grab.

In his letter, Mr Gleeson said his resignation did not mean he withdrew any of the positions and claims he made in “matters of controversy” between himself and the attorney.

It would in fact enable an objective analysis of the issues he’d raised.

“I also make perfectly plain that I reject absolutely each and every attack and insinuation that has been made in recent times upon me personally, or upon my office, by government members of parliament, including you, in the Senate committee process,” Mr Gleeson wrote to Senator Brandis.

George Brandis: This is the “proper course of action”. Photo: AAP

Senator Brandis, who announced the move on Monday, said Mr Gleeson’s resignation was the “proper course of action”.

Labor accused the AG of pushing Mr Gleeson out of office to save his own skin, saying the Commonwealth had lost a great legal mind.

“Senator Brandis should be condemned for his reprehensible and scandalous conduct,” Shadow Attorney-General Mark Dreyfus said in a statement, adding the minister should be sacked.

Opposition Leader Bill Shorten said Mr Gleeson was an honourable man who was pushed out of office by a dishonourable government.

“(Malcolm) Turnbull should hang his head in shame,” he tweeted.

Cabinet minister Christian Porter pointed to revelations Mr Gleeson had spoken to Mr Dreyfus during the caretaker period earlier this year without telling the AG.

“Trust is one of those streets that goes both ways,” the former West Australian attorney-general told Sky News.

The solicitor-general’s job comes with a $731,140 annual pay packet.

Mr Gleeson will step down from the job on November 7.

-AAP