New Zealand’s justice minister resigned on Monday after police charged her with careless driving and refusing to accompany a police officer after a car crash.

Kiri Allan was involved in the crash shortly after 9pm on Sunday in Wellington, the prime minister, Chris Hipkins, said, and she was detained at the central police station before being released four hours later.

Police have charged her with careless use of a motor vehicle, and refusing to accompany a police officer, and she has been summonsed to appear in court at a later date. Allan was handed an infringement notice for excess breath alcohol between 250mcg and 400mcg.

The incident involving Allan was the latest in a series of missteps and scandals involving government ministers less than three months out from national elections. Polls indicate the conservative opposition has pulled level or moved slightly ahead of the incumbent liberals in what promises to be a close race.

Once considered a rising star of the Labour party, Allan had recently taken time off for her mental health after being involved in a public split with her partner and accusations of poor working relationships with staff.

Hipkins said he spoke to Allan on Monday morning and told her that he thought she wasn’t in a fit state to remain a minister and that it was untenable for a justice minister to be charged with criminal offending. She agreed and resigned her ministerial roles, Hipkins said.

For now, Allan remains a member of parliament.

“While her alleged actions are inexcusable, I’ve been advised she was experiencing extreme emotional distress at the time of the incident,” Hipkins said. “Her recent personal struggles with mental health have been well documented and it appears some of those issues came to a head yesterday.”

Allan said she was sorry for her actions and was heading home to consider her future in politics. “Over recent weeks I’ve faced a number of personal difficulties. I took time off to address those, and believed I was OK to juggle those challenges with the pressure of being a minister,” she said in a statement. “My actions yesterday show I wasn’t OK, and I’ve let myself and my colleagues down.”

Last month, the transport and immigration minister, Michael Wood, resigned after failing to disclose a possible conflict of interest with stock he owned. In March, the police minister, Stuart Nash, was sacked after it came to light he had given confidential information to donors. In May, the customs minister, Meka Whaitiri, was fired after switching allegiance to another political party.

Hipkins took over as prime minister in January after his predecessor, Jacinda Ardern, stepped down. New Zealand’s elections will be held on 14 October.

The headline and introduction of this article were amended on 24 July 2023 to remove a reference to Allan being charged with resisting arrest. They were further amended on 25 July 2023 to clarify that Allan was charged with careless driving, not reckless driving.