Labour is promising another 300 frontline police officers, and new laws to crack down on gangs, if it wins the election.

But the commitments have been met with a warm but 'believe it when I see it' reaction from police and justice advocates.

And National's police spokesperson Mark Mitchell is deeply sceptical about Labour's delivery. He says an increase in officers is nothing compared to the increase in gang members, violent crime and retail crime.

"Numbers are important, in terms of a law enforcement agency like our police. But the point I'm making is that Labour have just got no credibility around public safety. I don't pay much attention to what they're doing at all."

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