Accepting the prosecution would allow clarification about what was considered a bribe and when a gift became a bribe, and clear up whether a spouse or partner of an elected official should have to declare gifts.
Referring to previous private prosecutions Mr McCready has laid he described himself and his company, the New Zealand Private Prosecution, as a "creditable [and] competent prosecution authority to which the public place increasing confidence and support".
Mr McCready has already laid charging documents at the court, alleging the mayor accepted a bribe for himself and his wife in not disclosing free hotel rooms and upgrades from SkyCity between November 2010 and November last year.
At the same time Mr Brown was publicly advocating the pokies-for-convention-centre deal.
Over the weekend Mr McCready found out that under the relevant section of the Crimes Act he would have to apply to the Attorney-General, Christopher Finlayson, for permission to take the prosecution.
A spokesman for Mr Finlayson said in practice, authority for such a decision was delegated to the Solicitor-General, Michael Heron, QC.
Mr McCready also said last week he was considering laying charges against Mr Brown's wife Shan Inglis, alleging she was a party to her husband's offending.
Instead Mr McCready will, for now, only pursue Mr Brown.
Mr McCready could not be reached for comment today about why that was.
Meanwhile, Mr Brown told RadioLive this afternoon he and his wife were "a very, very tight team".
"Some people might find that a bit difficult to understand but we are," he said.
"We love each other, we've been through a lot in our lives ... and I've provided her with the most difficult challenge, and she has made a decision to be with me and to keep us together."
He said there was "a lot of talking and discussion going on" in their marriage after his affair with council worker Bevan Chuang was exposed last year, but added "we are working it through" and his wife "continues to love me and support me".
Mr Brown also cracked a joke about how he missed going to Friday's Big Day Out because "I can't accept free gifts".