UPDATED 8.58AM Police Minister Judith Collins says the reason police are not turning up to 'dine-and-dash' thefts is because the country needs a larger police force.

There has been heavy debate between New Zealand First and National in Parliament over whether New Zealand should increase police numbers.

Winston Peters contends John Key has been a massive failure on the topic of law and order.

Recently police in Auckland decided not to investigate at least two restaurant 'dine-and-dash' thieves, saying it was a civil matter.

Judith Collins said it is one of the outcomes of low police numbers.

"I obviously can't get involved in individual cases, but I would say that that is probably an issue, one of the indicators around the fact that we do need more police".

Mrs Collins said the government hasn't kept up with its own goal of one police officer for every 500 people, there's now around 400,000 more people than in 2008 which equates to one officer to every 526 people.

She said domestic violence rates have doubled in the last eight years, it now takes up 42 percent of frontline officer's time.

"Police now attend over 100,000 family violence call outs a year, and the more we talk about family violence, the more people are going to report it."

Mrs Collins said she's in talks with the Prime Minister over increasing the numbers.

LISTEN ABOVE: Police Minister Judith Collins speaks with Mike Hosking

Meanwhile, the Police Association says it was pleased to see the hearty debate in the House yesterday.

President Greg O'Connor said police have become more efficient in the way they use staff and technology.

"And to some extent that has masked the decrease in the population-to-police ratio, however now we're seeing crime increasing and the population increasing while police numbers remain stagnant."

Mr O'Connor said parties across the political spectrum have different views on how many more police are needed - but what's important is the issue is out in the public arena.

He said 300 extra staff were added to Counties Manukau in 2008, and it made a huge difference.

Mr O'Connor said if that number were prorated across the country, New Zealanders would be a lot safer.