Auckland Council says years of hard work in reducing gaming machines in the city will be undone by the SkyCity Convention Centre deal.
In July, SkyCity signed a deal with the Government to pay for a $402 million centre in Auckland. In return, the Government extended its Auckland casino licence until 2048 and allowed it to operate 230 more gaming machines.
The project still needs approval from Auckland Council to go ahead.
In a draft submission on the New Zealand International Convention Centre Bill, which is before select committee, the council says the deal will set back Auckland's sinking lid policy of reducing the number of gaming machines by four to five years.