Independent senator Lidia Thorpe says she sustained serious injuries from an assault at a public event earlier this year, resulting in a prolonged absence from the Senate.

The senator disclosed details of the alleged incident after The Australian newspaper questioned why she had missed several consecutive sitting days, but said she had not wanted to make it public.

"I sustained serious nerve and spinal injuries in my neck, which required spinal surgery and a plate to be inserted. There's a scar on the front of my neck from this," she said in a statement provided to the ABC.

"I was ordered by the doctor not to travel and could not attend parliament after I sustained the injury and during recovery from surgery. My doctor told me to take time off work.

"I hadn't yet decided yet whether to disclose this publicly. The matter is still under police investigation. I would have preferred to keep this matter private and I will not be commenting on it further at this stage."

A spokesperson for the senator told the ABC the alleged assault took place at the MCG but did not provide further details.

Coalition questions validity of Thorpe's affirmation

The revelation comes after the Coalition issued a formal request to Senate President Sue Lines on Friday to review the validity of Senator Thorpe's affirmation of allegiance, a constitutional requirement for all senators.

On Wednesday, Senator Thorpe told the ABC she swore allegiance to the Queen's "hairs and successors" instead of "heirs and successors," adding she was unsure "where that stands" following the Queen's death.

She walked away from that position on Thursday, telling Sky News she had read the word "heirs" on the written affirmation she signed, but had mispronounced it owing to a grammatical error.

In a letter to the president, opposition Senate leader Simon Birmingham said Senator Thorpe had "proudly declared that she did not properly make the affirmation".

He said this was "deeply concerning and does bring her eligibility to participate in the proceedings of the Senate into question…"

"The Coalition believes this matter must be resolved so that the integrity and authority of the Senate is maintained.

"On behalf of Coalition senators, I therefore ask you to review this matter and to consider whether Senator Thorpe is currently eligible to take her seat in the Senate."

The president deemed Senator Thorpe's affirmation valid at the time despite the mispronunciation but has scope to review this finding if asked to do so by a senator.

Senator Birmingham also requested the standing orders, which govern the conduct of senators in the chamber, be broadened to capture "disruptive and disrespectful protests by senators."

Labor's manager of Senate business Katy Gallagher on Thursday signalled openness to discuss options with the Coalition to discipline Senator Thorpe after she interrupted a royal reception earlier this week but added no such discussion had yet been had.

In his first public remarks following the royal reception, Prime Minister Anthony Albanese said Senator Thorpe's "outburst was of course about Lidia Thorpe" and added it was "rude, outrageous and entirely inappropriate."

Thorpe defends Senate participation

Senator Thorpe has said she felt she had no other way to get her message across, having previously requested a meeting with the king.

"I wanted to send a message to the king, I got that message across, the whole world is talking about it and my people are happy," she said.

In a statement on Friday, she said she remained committed to participating actively in parliamentary proceedings.

"When I haven't been present in parliament, I have still been engaged with and following the legislative agenda, and ensuring that my voting positions are reflected in the vote outcome through pairing arrangements," she said.

"Pairing" is a process where parliamentarians who are absent for legitimate reasons arrange for an opposing senator to sit out of votes.

During Senator Thorpe's absence in August and September, the Hansard record shows several crossbenchers moved motions or made other contributions at her request.

"Despite what some say, I do not take my position in the Senate lightly. I am committed to my responsibilities and duties as an independent senator, and my small team is incredibly hard-working and diligent."