Scott Morrison rules out seeking Solicitor-General's advice on Christian Porter rape allegation

Attorney General Christian Porter has strenuously denied claims that he sexually assaulted a 16-year-old girl in Sydney in 1988 - when he was 17 years old.

Prime Minister Scott Morrison. Source: AAP

Prime Minister Scott Morrison has ruled out seeking advice from the Solicitor-General over a historical rape allegation made against Attorney-General Christian Porter.

Mr Porter has strenuously denied claims that he sexually assaulted a 16-year-old girl in Sydney in 1988 - when he was 17 years old.

Former Solicitor-General Justin Gleeson has suggested the government seek legal advice on whether Mr Porter is a fit and proper person to hold the Attorney-General position.

The Solicitor-General provides advice to the government on legal matters.

Mr Morrison said he had not received this advice from his office.

"He is entitled to his opinion on this, but that is not the advice I have been provided at any time during the course of managing this matter," he said.

Mr Morrison said Mr Porter was an "innocent man" under Australia's legal system and a "fine" attorney-general and industrial relations minister.

“He is an innocent man under our law,” Mr Morrison said.

"To suggest there should be some different treatment applied to him, based on what had been allegations that the police have closed the matter on, I think it would be grossly inappropriate to take actions against him on that basis."

Mr Morrison has dismissed calls for an independent inquiry into the allegations against Mr Porter saying the process would be contrary to the "rule of law".

However, some legal experts have questioned the basis of Mr Morrison's justification for not holding such an investigation given the circumstances surrounding the allegations.

The South Australian coroner is investigating the circumstances surrounding the woman's death and is currently considering whether to conduct an inquest.

Labor, the Greens, independent politicians and former prime ministers Malcolm Turnbull and Kevin Rudd have supported calls for an independent inquiry to go ahead.

Mr Porter - who is currently on stress leave - does not intend to step aside from his position and warned that he has become a victim of trial-by-media.

He has also raised concerns that the process of an independent inquiry would force him to "disprove something" that he claims "didn't happen".

Mr Morrison said he "wouldn't consider moving" Mr Porter aside from his role of attorney-general.