However, Key has consistently said councils' "sinking lid" policy on non-casino gaming machines means the total number of machines in New Zealand will fall despite the increase at SkyCity.
This morning he downplayed the prospect the deal would fuel more problem gambling.
"Assuming this deal will get through at broadly the number of pokie machines that we've been talking about, that stops that decline for a couple of years but overall the number of pokie machines is falling and the host responsibilities are very strong on an operator like SkyCity so I think we can cover that bit off."
Key, who has seen at least two drafts of the Auditor-General's report, says he is not concerned by its findings.
"In my view there's no political element to it."
He said detailed negotiations with SkyCity had been on hold until the report was released and whether the deal went ahead depended on whether SkyCity was still serious about it.
The casino operator last week said it was willing to proceed, "provided an acceptable return on capital can be delivered from the total project".