Greens senator Lidia Thorpe will seek to refer herself to parliament's powerful privileges committee, over her undisclosed relationship with a former member of the Rebels outlaw motorcycle gang.
The ABC revealed last week that Senator Thorpe "briefly dated" a former president of the club's Victorian chapter, while also serving on a parliamentary law enforcement committee.
That committee was receiving confidential briefings and documents, however, there is no suggestion that Senator Thorpe passed information to anyone who should not have received it.
Within an hour of the ABC's report, Senator Thorpe had resigned as deputy leader of the Greens in the Senate.
On Monday she told the Greens party room that she would write to the President of the Senate, Sue Lines, requesting a referral to the Senate committee of privileges.
"The Greens Party Room backed my decision today," Senator Thorpe said in a statement.
"I am more than willing to participate in any inquiry."
The letter is only the first step in the referral process.
The Senate President will then decide if it meets the criteria for referral, and if it does, the upper house needs to agree to send the matter to the committee.
The committee is responsible for examining the conduct of parliamentarians, and sessions are typically held in private as it compiles its report.
Coalition frontbencher James Paterson has called on the Greens to publicly release Senator Thorpe's letter to the Senate President.
"It is important all senators are able to understand the grounds on which she's seeking to refer herself to the privileges committee," he said.
"What standing orders does she believe she has breached that need to be investigated by the committee?"
He also called on the party to allow a full discussion on the issue in Parliament.
"They should not allow procedure in the Senate to shut down debate on this matter, and any Senator who wishes to make a contribution on these very important matters should be free to do so."
Last week, the chair of the law enforcement committee, Labor senator Helen Polley, launched an internal investigation into any potential conflicts of interest.
That inquiry will include an examination of the minutes of previous meetings.
The federal opposition has also flagged it will seek to move a censure motion when parliament returns tomorrow.
Censure motions allow MPs to express their disapproval of their colleagues but don't have any direct legal consequences.
It is not clear yet if the government will support the motion.
