On Sunday, Mr Brown had just received a text from the mayoress, Shan Inglis, when another text from an unknown number came through. "You said we would win by 15. Told you to be more optimistic ha," the text read.
Evidently, Mr Brown was confused as to who had texted him, and replied, thinking it was his wife, with: "On way. Picking up coffee. U want? Good meet."
Mr Key jokingly replied: "This is john key and I know it's the full service but even I think coffee delivery is a step too far."
Mr Brown, after he realised it was the Prime Minister and not his wife, was able to laugh off the situation - which could have been much worse.
"Well, what a hoot. Shan sent me a text just before yours and I was rushing to reply. Bloody hell, way too fresh behaviour towards the PM!" Mayor Brown replied.