Stuart Nash has quit as New Zealand First’s candidate for Napier, hours after refusing to apologise for a text message that described his National rival as lazy for taking maternity leave.

New Zealand First leader Winston Peters confirmed the resignation in a social media post on Wednesday night.

“Stuart Nash has offered his resignation as a candidate and we have accepted,” he said.

The announcement came about an hour after Prime Minister Christopher Luxon ruled out Nash ever serving as a minister in a government he leads.

“Whether reports of Stuart Nash’s resignation as a NZ First candidate are true or not, I am making clear he will not serve as a minister in my government,” Luxon said in his own social media post.

“After several instances of poor behaviour, some politicians will claim he has changed. His lack of contrition after comments about one of my MPs’ maternity leave this evening shows he hasn’t.”

Earlier on Wednesday, Luxon had called Nash’s remarks sexist and said the former Labour minister was “channelling the manosphere”.

The controversy centres on a text Nash sent to former attorney-general Chris Finlayson on 14 July about first-term Napier MP Katie Nimon, who returned to work this year after having a baby.

In the message, Nash wrote that Nimon “took nine months off on full pay, went back for a week, then took another month off”, called her the “laziest MP I have ever come across”, and described her as “nice woman but ill-suited to the rigors of being an electorate MP.”

Nimon told media the comments were “absolutely” sexist, though she said her first reaction was to laugh because they were untrue. She said she returned to part-time electorate work after about 10 weeks and was back in Wellington after six months.

“I’ve achieved more with National for Hawke’s Bay in three years with a baby than he has in nine years,” she said.

Nash did not apologise on Wednesday. In a statement, he said the campaign was “about who shows up and delivers for Napier” and that he wanted to be judged on his track record, achievements and work ethic. He said he had “real respect for any working parent raising a newborn alongside a demanding job”.

Nash, 58, held Napier for Labour for three terms before being sacked from Cabinet in 2023 by then prime minister and current Labour leader Chris Hipkins. He joined New Zealand First in May and had been set to contest the seat against Nimon at November’s election.

It is the second controversy involving Nash and his comments about women in the past year. In September he described a woman in crude anatomical terms during an interview with The Platform, remarks he later apologised for. That episode cost him a place on a government trade trip to the United States.

The remarks this week drew condemnation across Parliament. Finance Minister Nicola Willis said the suggestion that people raising children could not cope with leadership was outdated, while senior National MP Chris Bishop called Nash a “sexist dickhead” in a social media post. Green Party co-leader Marama Davidson described the comments as “pretty vulgar”.