Auckland Council is encouraging cat owners to microchip their pets, but that's being seen as a revenue-gathering exercise.

The council's reviewing it's Regional Pest Management Plan.

Biosecurity manager Phil Brown says some non-microchipped cats will be euthanised at sites of ecological significance.

Cat Foundation chairwoman Anne Batley-Burton says told Rachel Smalley the council's doing this because they want to cull cats and this is their justification for it.

She says this is revenue gathering, is going to cost people a lot of money and won't make any difference to whether a cat chases a bird or not.

LISTEN TO THE FULL INTERVIEW WITH RACHEL SMALLEY ABOVE