The heated debate over Mr Barr's self-admitted threat to Mr Hanson dominated the final day of Legislative Assembly sittings this week as politicians across the party divide flung insults at each other.

It stems from a heated "exchange" between the two long-term political foes during a committee hearing late last year, in which Mr Hanson claimed Mr Barr was putting rates revenue into his pocket, as treasurer.

Mr Barr then asked Mr Hanson to "take it outside", later clarifying he meant "into the chamber", before Mr Hanson asserted his role as committee chairman, to which Mr Barr said: "For the time being, yes".

Mr Hanson asked him if the comment was a threat, to which Mr Barr responded that "it is, yes".

Liberal MLA Andrew Wall on Thursday put a motion to set up a privileges committee to examine Mr Barr's conduct, and after hours of debate, ultimately an amended motion was passed, with Mr Barr's and Mr Hanson's conduct to instead be investigated by parliament's Administration and Procedure Committee.

But the final motion also noted Mr Barr's threat had breached the Standing Order related to threatening members, as well as his withdrawal of the comment, and that all related matters be examined and recommendations made to the Assembly.

Mr Wall said he, and the Opposition, believed Mr Barr's threat was a "clear cut breach of the Standing Orders" and a display of "cowardice" that amounted to "bullying" and may have brought the Assembly into contempt.

Mr Wall said given Mr Barr had confirmed his comments were a threat during the hearing, it was incumbent upon the Assembly to determine whether such language and threats were acceptable.

Mr Barr rejected Mr Wall's claim he had displayed "cowardice" and said he made the original comment, with the addition of the words "into the other chamber", only because Mr Hanson had said repeatedly he had "pocketed" public funds.

He said he asked Mr Hanson to withdraw the comment some 13 times during the hearing and he took offence at the "clear imputation" he had personally "trousered" the money, challenging "anyone in this place" that if they were accused on similar terms they "would not react".

But Mr Barr said he would withdraw his comment, if Mr Hanson withdrew his and he believed the matter was better dealt with under an ongoing review of parliament's Standing Orders, rather a privileges inquiry.

While Mr Hanson said he executed a "robust line of questioning" during the hearing, his actions, as confirmed by the Assembly's Clerk and the relevant committee secretary, were within the rules.

But he did not withdraw his comments, instead saying that as chair of the committee at the time, Mr Barr had questioned his ruling 32 times during the hearing and then threatened him, but was now "trying to paint himself as the victim".

Greens leader Shane Rattenbury, who described the whole matter as "a very tawdry affair", put an amendment to Mr Wall's motion, which would have widened the privileges inquiry to also include Mr Hanson's conduct and "any other relevant matters".

He said that it seemed both Mr Barr and Mr Hanson intended to "double down" on their positions and if the Assembly believed a privileges inquiry was the way to go, it should include both members' conduct.

Despite his comments, Mr Rattenbury hit out at Mr Hanson, saying his speech "completely defies the character he so regularly displays in this place".

He said saying that over the 10 years he had watched Mr Hanson in the Assembly, he regularly "belittles" other members across the chamber, in an "underhanded" way, just quiet enough so the Speaker would not hear and demand a withdrawal.

Mr Rattenbury likened Mr Hanson's behaviour to "the way bullies behave in the old school yard", where they "needle" another student behind the teacher's back "until finally that person retaliates and then they run to the teacher and say such and such has hit me Ma'am, it's not fair".

But Mr Rattenbury's motion was voted down, after Mr Wall proposed amending his original motion to instead refer the matter to the procedural committee.

A further amendment by Mr Barr also resulted in the addition of wider "context" and quotes from Hansard of the exchange added to the final motion agreed to.

But Mr Barr's attempt to remove the clause explicitly mentioning his breach of the Standing Orders over the threat failed.