Watch: Prime Minister Chris Hipkins gives update on Kiri Allan's resignation

Prime Minister Chris Hipkins has spoken to media about the resignation of Kiri Allan as justice minister.

Allan was charged with careless use of a motor vehicle and refusing to accompany a police officer, following a car crash in Wellington on Sunday night.

She was also issued an infringement notice for having excess breath alcohol between 250 and 400mcg.

Hipkins said Police Commissioner Andrew Coster advised the police minister that Allan had been taken into custody around 10pm.

"I was advised shortly there after."

Hipkins said: "While her actions are inexcusable I was given information that she was experiencing extreme emotional distress at the time of the incident. My initial concerns last night were for her immediate safety and wellbeing.

"It appears that some of her personal struggles came to ahead yesterday and were contributing factors in this incident."

Hipkins said he spoke to Allan just prior to 7am this morning.

"I advised her that I did not believe that she was in a fit state to hold a ministerial warrant, she expressed remorse and had already sent me a message just before that indicating that she intended to resign.

"She understood that retaining her ministerial warrant was untenable, especially for a justice minister to be charged with criminal offending."

Allan was heading home and would be taking time to consider her future in politics, he said.

"I recently provided Kiri with the opportunity to address her mental health issues. After taking some time out she told me she was ready to return to work.

"Those who saw her last week, in the House and here in the theatrette, launching the ram-raid policy, would have observed her at the top of her game. Last night's incident however, is evidence that there are not always quick fixes when it comes to mental health and things can flip very quickly and without warning.

"The best thing for Kiri right now is to focus on her whānau and her wellbeing and to be away from Parliament."

Hipkins said he would confirm the reallocation of her portfolios later today.

Asked how damning this was for Labour, three months out from the election, Hipkins said that had really not been part of his thinking at all in the past few hours.

When asked how much he was to blame, as it was ultimately his responsibility and if Allan came back to work far too soon, Hipkins said: "I don't think you can form that judgement."

"I required Kiri to take some time off, you may recall at the time she was resistant to that. She came back to work after receiving counselling, with indications, very strong indications to me that she was ready to take on the job and you would have seen last week that that actually I had no evidence to question that."

Allan was provided with coaching, counselling and support, he said.

"I spoke to her on the phone this morning, it would be fair to say it was a difficult conversation.

"She's clearly not in a good space so it was not a long conversation and we have people with her and around her supporting her."

Asked if the government retained the confidence of the public and whether it was time for a snap election given Labour had lost a number of ministers, Hipkins reiterated the current election date and said that had not been front of mind for him in the past few hours.

He did not think now was the right time to be bringing new people into the ministry this close to the general election.

"I have absolute confidence that the remaining ministers in the ministry will be able to cover that workload until election day."

Hipkins notified late last night

Hipkins said he received a series of calls after 10pm on Sunday night about the incident.

"I received a phone call from my chief-of-staff just after 10 o'clock, then while I was on the call to him I got a call from the minister of police who had further information and so we then had a series of phone calls. I wasn't able to speak to Kiri directly, she was still at the police station.

"The facts weren't particularly clear last night, they have become clearer this morning - I guess what had happened was contested and so now we've got clarity around that.

"I would note that probably the bit that doesn't seem to be contested by anyone is that she was in a very distressed state."

Hipkins said he made sure Allan had been receiving counselling and professional support before her return to work.

"Ultimately, mental health is incredibly challenging in the sense that when someone comes to you, says that they feel they're on top of things, exhibits clearly all of the signs to suggest that they are, that puts you in a very, very difficult position and as you would have seen last week, Kiri was showing signs that she had gotten on top of things.

"I think that it's a terrible set of circumstances."

He did not speak to clinicians directly and was relying on information from Allan regarding her being fit to return.

Hipkins said he had to seek clarity on what exactly had happened and if Allan had been the one driving.

"I didn't get clarity on that until this morning.

"The problem was that I couldn't speak to her last night but there was some suggestion that she may have said that she wasn't driving, now of course, I couldn't verify any of that because I couldn't speak to her so until I actually knew what had happened and had it verified by the police and then ultimately verified by her, I wasn't in a position to really do anything, form any judgement on that.

"She has been charged and has not contested that she was driving."

Everyone, including himself, was still processing this, he said.

"But we will need to focus on the job that we have ahead of us. Right now I know everybody this morning is very concerned for Kiri, we'll make sure that we'll get support around Kiri, we'll make sure that we manage our way through this process and then of course we will need to focus, we've got a job to do as a government."

Hipkins said he was "very sad" for Allan.

"Kiri is an incredibly talented person who clearly has been battling some demons and has not won that battle.

"As I've indicated, I'm gutted for Kiri, I'm concerned for her wellbeing, that's the primary concern, later on this afternoon we can talk about the wider implications of that."