Four shortlisted flag designs will be put to the vote in November but plots to gerrymander the referendum results are already under way.
The Flag Consideration Panel yesterday released the four shortlisted designs which voters will rank in order of preference in a postal referendum in November.
The most popular design from that referendum will then go up against the current flag next March.
Three of the short-listed designs feature the silver fern and have already come in for criticism as opponents of the process plan to vote strategically by way of protest.
Labour's flag spokesman Trevor Mallard said the koru was "absolutely awful" so it was likely he would vote for it as a protest vote. Officials had earlier warned there was a risk that opponents of change could vote for the least attractive option to try to ensure a weaker contender against the current flag.
The RSA and NZ First are also both urging opponents of change to either destroy or spoil their ballot papers in the first referendum and Labour leader Andrew Little said he will not vote.
Flag Consideration Panel chairman John Burrows said it would be a shame if attempts to skew the results emerged. "I hope there won't be much gerrymandering because I think people have got to see what an important occasion this is.
"It's the one chance people have in their lifetimes to do it. So to actually waste a vote for political or other reasons I think will appear to most people as unpalatable and unattractive."
Mr Mallard said the Kyle Lockwood designs were too complicated.
Despite that, the two Lockwood designs were the favourites of Black Caps captain Brendon McCullum and Lady June Hillary. Lady June said that while she would prefer to keep the current flag, if there was a change, she liked the red, white and blue Lockwood design. She understood some wanted change, but she was fond of the Queen and believed the Union Jack was part of New Zealand's history. Sir Edmund Hillary reached the peak of Everest at the time of Queen Elizabeth's coronation and she later knighted him. The Queen also attended a service for Sir Edmund Hillary alongside Lady June at Windsor in 2008 after his death.
The Lockwood designs were also popular in an online survey on nzherald.co.nz yesterday. Of just over 12,000 votes by last night, Lockwood's black, white and blue flag had 33 per cent and the current flag was on 28 per cent. Lockwood's red, white and blue design was just behind on 22 per cent. The other two contenders were well back - the koru had 4 per cent and the black and white fern was on 6 per cent.
One notable omission from the short list was the silver fern on a plain black background which was Prime Minister John Key's original pick.
Mr Key said he was happy without it. He went cold on the black flag after it was mocked for being similar to the Islamic State flag.
His preferences were the two by Kyle Lockwood because they contained the fern. "I like the Southern Cross because I think it's got that connection with the old flag."
Gareth Morgan said it was clear the panel had gone with the more popular options. "That's really important for getting the required numbers for change."
Former Black Caps captain Stephen Fleming chose the black and white stylised fern as his favourite. That design includes a fern which is trademarked and used as a logo by Government groups.
Change the Flag spokesman Lewis Holden said the use of it as a logo might damage its chances although the maple leaf design on Canada's flag was a biscuit tin logo.
What happens next
November 20 to December 11:
First referendum. Voters asked to rank the four shortlisted designs in order of preference. A postal referendum.
March 2016: The most popular of the alternative flags is pitted against the current flag in a second referendum.