NSW Premier Chris Minns has confirmed Labor will field a candidate at the upcoming Kiama by-election after Gareth Ward resigned on Friday morning.

After repeated calls over the past two weeks for him to fall on his sword, Ward vacated the seat less than an hour before NSW Parliament was due to vote on a motion to expel him.

He remains in custody in jail in the Hunter after being found guilty late last month of four sexual assault offences.

Minns said Labor was keen to regain the seat of Kiama, which they have not held since 2011 when Ward was first elected under the Liberal Party banner.

He retained the seat as an independent candidate in 2023 even though he had been charged by police.

There was a swing of more than 11 per cent against Ward but he managed to hold onto the seat ahead of Labor rival Katelin McInerney be a slender margin.

McInerney is expected to be a frontrunner for pre-selection when Labor meets in the near future to nominate their choice for the by-election, likely to be held in early October.

"We're certainly looking at it very closely ... I expect us to run and give the voters of Kiama a choice, whenever that byelection will be," Minns said.

“They’re independent minded down there, they’ll make their own decisions.

Katelin McInerney.

“We would be going in with our eyes wide open. And this would be a very, very tough contest for Labor.

"We'd be complete mugs to expect that this is anything other than an incredibly difficult contest.

"It'd be just so arrogant for us to roll into a seat that in 2019 the Liberal Party won on primaries, and in 2023 an independent won, notwithstanding the fact that he was facing incredibly serious charges."

Minns castigated Ward for his refusal to resign until the last minute.

The 44-year-old launched an injunction in the NSW Supreme Court on Monday to prevent his expulsion but that was lifted after the Court of Appeal on Thursday ruled in favour of the State Government.

"We believe this resignation should’ve come earlier,” Minns said.

“The circumstances relating to it meant that a lot of time, effort and energy was spent in the NSW Supreme Court, proving what most people who live in this state would’ve known instinctively.

"And that is that if you’re convicted of some of the most serious charges, sexual assault, in NSW, you can’t sit as a serving Member of Parliament drawing a parliamentary salary.

“How can you represent your community from behind bars in Cessnock? How can you do constituent interviews?

"And the government and the Parliament needed to make a decision to protect the integrity of the legislative assembly. We’ve done just that.”

There have been reports suggesting that the Liberal Party will not contest the seat due to the reputational damage of being associated with Ward for more than a decade.