UPDATED 4,41pm: The shortlist of flag designs for what could be New Zealand's next flag are about to be unveiled.

Prime Minister John Key has confirmed the list of designs has been narrowed down to four.

"Cabinet got I guess the heads up of what the four were like today, that's as per the process that was set out. We've accepted those four recommendations made by the panel and they'll be released tomorrow morning for public discussion." 

They'll be released publicly tomorrow.

John Key thinks they're a good reflection of what were over 10,000 designs.

"I think there's two or three there that could potentially be a new New Zealand flag, and I think it will be for New Zealanders to ultimately decide."