Ardern grapples with NZ crime challenge

Jacinda Ardern has delivered an impassioned defence of her government's record on crime after national protests sparked by the murder of a dairy worker in her electorate.

The dairy, or what New Zealanders call corner stores, is a cherished part of Kiwi culture and, more recently, a crime flashpoint due to an uptick in opportunistic ram-raids and offences.

On Monday, dairy workers walked off the job for two hours in solidarity at the death of Janak Patel, who was murdered outside the Rose Cottage Superette in inner Auckland last week.

Hundreds gathered outside Ms Ardern's office in Auckland, flowing onto the street, chanting "Enough is enough" or "Jacinda must go" according to reports.

More still assembled outside deputy prime minister Grant Robertson's office in Wellington, while others further afield posted signs on their shopfronts in Mr Patel's honour.

Ms Ardern and hundreds of others attended Mr Patel's funeral on Sunday

"An individual's life has been taken and a family's life has been shattered. It was deeply, deeply moving," Ms Ardern said.

Police have charged a 34-year-old man with murder and aggravated robbery and two others with robbery in relation to Mr Patel's death, with Ms Ardern saying it was important that "justice is done".

The murder comes amid a national debate around crime and punishment which is likely to shape next year's election.

Particularly young offenders - some as young as 10 - are targeting dairies as well as liquor stores, jewellers, and tech businesses in smash-and-grab burglaries that are costing retailers dearly and can end in violent confrontation.

Mr Patel's case was particularly tragic.

His funeral service heard he and his wife dreamt of running their own business and relocated to Auckland just a week earlier to mind the dairy while the owners were away.

The crime uptick would be a state matter in Australia but in New Zealand, without a federal system of government, the responsibility - and the blame - falls to the prime minister.

Despite hiring hundreds more police officers, the government has struggled to convince Kiwis it can keep streets safe.

The prime minister sacked police minister Poto Williams in June, citing a failing "narrative" around crime, replacing her with senior minister and trusted friend Chris Hipkins.

On Monday, she announced $NZ4000 ($A$3700) grants to dairies to install fog cannons, and $NZ10 million ($A9.3 million) in broader crime prevention funding.

The government believes ram raids peaked in August as police were able to confront a small group responsible for most of the attacks.

However, each new ram raid or attack brings questions over Labour's approach to crime, with the opposition insisting it should harden up.

National party leader Chris Luxon, who visited Mr Patel's dairy on Saturday with flowers, has promised a series of tough-on-crime measures if he wins next year's election.

They include electronic monitoring ankle bracelets for 10-year-olds and a military-run boot camp for 15-year-olds should they re-offend.

Ms Ardern has pushed back against those measures, citing a lack of evidence.

"I think people would find it refreshing if for once they saw politicians not trying to outbid each other on policy but just doing what works," she said.

"History has told us boot camps don't work. They have an incredibly high reoffending rate."

On Monday, she struck out at critics who point at lower prisoner numbers to label her government soft on crime.

"If you compare toe-to-toe National and Labour's record, we've invested more in police consistently," she said.

"I am happy to debate this issue based on evidence and facts, but I will not - I will not - stand by and have anyone call this government soft on crime.

"We have been the opposite. Firm and fact-based."