Key said Goff would have to get public support to introduce Maori wards rather than relying on the Government to change the law which set up Auckland Council.
He said if the Government unilaterally changed the law it would run counter to wider local government legislation which left it to communities to decide on Maori wards.
"But for the Government to go out there and say 'there would be Maori wards' [in Auckland] I think would be a big step and it's not likely one we would like to take."
"If the Government wasn't prepared to straight out change the law then you might have to go back to the rules that apply to the rest of New Zealand. That requires community outreach and support. If that was something he wanted he'd really have to make the case and I think he'd have to make the case with the people of Auckland."
Key said Maori representation by the statutory board was considered the best option when the Super City was set up and he believed it still was.
Councils can introduce Maori wards under the Local Electoral Act. Councils can introduce Maori wards without holding a local referendum but that can be challenged by a referendum if there is significant opposition.
Historically National has opposed the Maori electorates in central Government - but policies to change that have been shelved since National has been in a governing arrangement with the Maori Party.