Gareth Ward will remain the Kiama MP until at least Friday - collecting his $3350 a week pay - after a NSW Supreme Court judge granted injunction orders against state parliament's lower house leader Ron Hoenig and Speaker Greg Piper.
The court order blocked the Labor government's plans to expel Ward from his seat in a vote slated for Wednesday.
Instead, the dispute will play out before the head of the Court of Appeal on Thursday after Labor sought an urgent relisting of the matter, concerned the initial judge had acted beyond her power.
Constitutional law expert Anne Twomey said court interference in a matter before parliament is uncharted territory for Australia's first state.
"It is certainly highly unusual," the University of Sydney professor emerita told AAP.
"It is even more extraordinary before a matter has actually been dealt with by the (lower) house."
Such tussles are not common because of the principle of comity - meaning courts and legislative bodies respect each other's jurisdictions and do not overstep their institutional boundaries, Dr Twomey explained.
The emergency injunction issued late Monday was a "freezing position" for Ward until the court can make a more considered decision.
The former families minister was jailed on July 30 after a jury days earlier found him guilty of sexual intercourse without consent and three indecent assaults.
He has lodged an appeal against the jury's findings and will be automatically expelled if that appeal fails.
But Labor wants him gone immediately, aiming to utilise a rarely-used power for MPs to expel colleagues for "unworthy conduct".
It's been used four times in NSW - the last in 1969 for Alexander Ewan Armstrong - and just once in federal parliament.
Ward has continued to receive his salary since his conviction.
"Clearly, he's got no shame," NSW Premier Chris Minns told Sydney radio 2GB on Tuesday.
"It's an unconscionable situation to have someone who is currently sitting in jail in Silverwater convicted of serious sexual offences, who is demanding to remain a member of parliament and continue to be paid."
The premier warned a critical time factor was at play, with parliament due to rise on Friday evening and the lower house taking a break for four weeks.
Mr Hoenig - responsible for shepherding government business through the lower house - said all options were on the table to oppose Ward's motion and the court's "significant constitutional error".
The courts did not have the power to restrain MPs from bringing forward matters under parliamentary privilege, he said.
Had Wednesday's vote gone ahead, the Kiama MP could have appealed to the Supreme Court before a by-election was triggered.
Former attorney-general turned Opposition Leader Mark Speakman said the case raised "an interesting question" about the extent the state's courts can intervene in its parliament.
He reiterated support for Ward's expulsion, saying there was "no other choice" in light of the convictions.
The independent MP awaits sentencing for sexually assaulting an intoxicated political staffer after a midweek parliament house event in 2015.
The 44-year-old was also found to have sexually abused a drunken 18-year-old man at his South Coast home in 2013.
The most serious charge carries a maximum 14-year jail term.
Ward has held the Kiama electorate since 2011, winning three elections under the Liberal banner.
He secured the 2023 poll as an independent, despite having been suspended from parliament following his arrest.
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