The Police Association says a recent spate of attacks on retailers in Auckland demonstrates the need for more frontline police officers.
On Monday, a retailer was stabbed during an altercation with several teenagers outside the Otara Liquor Store.
The retailer has since been charged with assault.
And an Avondale Lotto shop owner is recovering in hospital from stab wounds after an incident on Friday.
The Police Association's vice president, Detective Senior Sergeant Chris Cahill, says a policy change is needed at police national headquarters, to ensure more officers go to the frontline, rather than community policing roles.
Chris Cahill says a rise in crime in some areas means it's not a surprise retailers are starting to take the law into their own hands.