NZ flag options side by side on Auckland Harbour Bridge
Aucklanders have got their first look at a large-scale version of the alternative flag.
The black and blue silver fern designed by Kyle Lockwood was hoisted over the Auckland Harbour Bridge on Friday.
It will sit alongside the current flag until the March referendum.
Other than the New Zealand flag, only three flags are normally allowed to fly on the Auckland Harbour Bridge: the Tino Rangatiratanga flag on Waitangi Day, the Australian flag on Anzac Day, and the Merchant Navy Flag on Merchant Navy Day.
NZ First leader Winston Peters was unhappy with the move, saying Prime Minister John Key was "grandstanding" to secure a vote in favour of change.
But the Government has argued it will help people compare the designs before making a final decision.
Voting for the final stage of the referendum opens on March 3 and closes on March 24.