The groups pushing for a law change for better control of cats insist it's "not a cat-killing exercise".
The SPCA and the Morgan Foundation, with the help of animal welfare and veterinary experts, have released a draft strategy outlining how to improve cat welfare while reducing their impact on wildlife.
"It's not cat-killing exercise, it's not a 'see if we can get rid of all the cats in New Zealand', it's an exercise to improve the lives of cats here, it's an exercise to help protect the unique wildlife in New Zealand," Auckland SPCA vet manager Dr Shalsee Vigeant says.
She says it's a juggling exercise to appease both cat owners and conservationists.
"Either way there's criticism no matter what group you're trying to protect, but I think what people need to realise is the overall goal is to be positive and help each of those groups."
Dr Callum Irvine of the New Zealand Veterinary Association says the plan includes management of domestic cats, strays and feral cats.
"We feel there's a need for national legislation, a cat management act or something along those lines that can put some fairly specific requirements in place, particularly around mandatory identification of cats and a requirement for de-sexing of cats in this country."
The Department of Conservation already has controls in place for feral cats, and Dr Irvine says the strategy aims to ensure they are disposed of humanely.
Roughly half of New Zealand households own cats, as well as 196,000 strays and an unknown number of feral cats.
He says local councils should be given the power to control cats in their area how they see fit, including possibly limiting the numbers of cats people own near sensitive wildlife areas.
"We've got a fairly laissez-faire attitude towards cat ownership in this country," he says.
Geoff Simmons of the Morgan Foundation says the strategy is urgently needed if the Government's serious about its aim to be predator free by 2050.
He says the new legislation must be supported by bylaws that allow councils to better manage cat ownership.
"We've already seen in Wellington the council is aiming for compulsory microchipping of all cats. It's been very difficult for them to do that under current regulations.
"It's about giving those councils that do want to take action the tools to do so."
He says some options for councils could include charging for registrations of cats and charging owners when lost cats are picked up and returned.
The groups aim to present the strategy to Government by the end of the year.