Hamilton West byelection: Gaurav Sharma's surprise exit hurts Labour's chances - Jacinda Ardern

Labour's ability to retain the Hamilton West seat has been compromised by Gaurav Sharma's explosive resignation from Parliament, according to Prime Minister Jacinda Ardern.

Sharma published a surprise social media post on Tuesday afternoon announcing his resignation from Parliament after an investigation by Labour's governing body, the New Zealand Council, recommended Sharma's expulsion from the party for "bringing the party into disrepute".

Sharma, who was expelled from Labour's caucus in August, claimed he had been informed by NZ Council members that the party planned to invoke waka-jumping legislation to kick him out of Parliament, but not until six months from next year's general election, by which time a byelection couldn't take place.

"I have sincere concerns that this underhanded move will mean people of Hamilton West will have no voice in Parliament for six months preceding the next general election," Sharma's post read.

Sharma confirmed he would set up a new centrist party to contest the byelection.

"Whether I win or not, that's a different case but regardless of that, I will put [up] a fight and I will stand up for myself," he said yesterday.

Ardern has repeatedly denied Sharma's account, saying the party hadn't considered invoking the waka-jumping legislation at any stage.

A statement from the Labour Party said Sharma's resignation "appears to conflate being potentially expelled from the Labour Party with being waka-jumped from the Parliament".

"There is no link between the two," it read.

Labour's New Zealand Council investigation recommended Dr Gaurav Sharma be expelled as member of the Labour Party. Photo / Getty Images

Speaking to media on Tuesday, Ardern said she wouldn't announce a byelection date until she received advice from the Electoral Commission, which she expected in the coming days.

She again contested Sharma's claim about invoking waka-jumping legislation and bemoaned the waste of taxpayers' money.

Each byelection costs the taxpayer an estimated $1 million, the Electoral Commission has said previously.

Sharma's success in the Hamilton West seat in 2020 formed part of the red wave that led to Labour candidates pulling off unlikely wins, caused by the popularity Labour was afforded through its management of the Covid-19 pandemic.

National's Tim Macindoe held the seat from 2008 until Sharma, who had failed to win in 2017, won it off him in 2020.

Dr Gaurav Sharma and Prime Minister Jacinda Ardern. Photo / Supplied

Ardern cited National's success in Hamilton West in her assessment of the challenge posed by the byelection.

"I'll let that record speak for itself as to the kind of contest it might be," she said.

"I think it's fair to say that Labour has at least in recent times, been an underdog in this seat."

She predicted it would be a "very robust" and "tough" byelection for Labour that hadn't been aided by the nature of Sharma's exit.

"We've had a Labour member who has not left on good terms and that does not reflect well for the local constituency."

Sharma's resignation came into effect from midnight on Tuesday. When it was announced in the House on Wednesday, a number of front-bench ministers - including Stuart Nash and Damien O'Connor - quietly clapped and smiled among themselves.

With a byelection date soon to be announced, political parties would be assessing their chances and whether they would submit a candidate.

National's Tim Macindoe held the Hamilton West seat between 2008 and 2020. Photo / Supplied

A statement from the National Party said the selection process is "underway" and the party would be "ready to go whenever [the byelection] is called".

National leader Christopher Luxon told the Herald a number of people had put their hand up to become National's candidate.

"There are a lot of candidates who have already expressed some interest over the course of the year of running in the Waikato or in Hamilton and we'll go through that process in the coming weeks once we're clear on when the date is.

"I'm confident that we'll end up with a really good local candidate who will run a great campaign there."

Labour did not respond to repeated requests for comment on its candidate selection plans.

An Act Party spokesperson said the board would meet in the coming days to decide whether the party would contest the byelection.

Act's Roger Weldon came in third in 2020, winning just three per cent of the vote.

The Opportunities Party's Hayden Cargo finished fourth, but he had since become the party's secretary and would not be running.

The Opportunities Party leader Raf Manji. Photo / Supplied

TOP leader Raf Manji confirmed the party would have a candidate in the byelection and they would be selected next week.

"Hamilton is a good seat for TOP, both candidates in the west and east did well," he said.

Manji said a full list of TOP candidates and where they intended to run in the general election would be released by the end of November.

A Greens spokesperson said the byelection would be discussed between the central party and the local branch before a decision was made. The party did not contest Hamilton West in 2020.

Te Pāti Māori/the Māori Party also didn't enter a candidate in 2020. A spokesperson confirmed the party's executive would soon discuss the matter.

New Zealand First president Julian Paul said the party's board would discuss the byelection at its next scheduled meeting.

The New Conservative party earned 1.5 per cent of the vote in 2020. Co-leader Ted Johnston said the party was considering options, including running a candidate "in conjunction with other parties or groups".

He believed Sharma should have joined New Conservative instead of forming his own party and confirmed he would open to discussing it if Sharma was willing.

Matt King of the newly registered DemocracyNZ said it had not been decided whether the party would contest the byelection.