MPs and Liberal Party staff could be forced to testify or expose their private correspondence as a result of the proceedings after mediation between the pair failed.
Deeming declined to comment on Tuesday. Pesutto’s office also declined to comment.
The opposition leader initially tried to remove the first-term MP in March for her role in the controversial Let Women Speak rally,which was organised by British anti-trans rights campaigner Kellie-Jay Keen-Minshull and gatecrashed by neo-Nazis.
Pesutto claimed Deeming hadassociated with organisers and speakers who shared platforms “with people who promote Nazi views or sympathies”,and that Deeming had failed to disassociate herself from them.
But the party roomagreed to a compromise under which she was suspended for nine months,costing her the position of upper house whip and the $20,000 pay rise that went with it.
Deeming was expelled from the party room weeks later,in a motion co-signed by five Liberal MPs,after shethreatened to launch legal action against the party and Pesutto.