Next week everyone of voting age will receive an official envelope inviting us to select a new flag. The sight of a voting form can be sobering. Suddenly the subject is no longer a conversation piece, it is a personal decision. With that realisation should come another: this is not a decision we get to make again. This two-stage referendum is the first time the public has been invited to choose the nation's flag. It can safely be assumed the chance will not come again.
It is just possible, but not likely, that the final vote will be so close that a future government might reopen the question. But that could happen only if there is a narrow vote for the status quo; a narrow vote for a new flag would be conclusive. We would never go back. A decisive vote for the status quo is the more likely outcome, according to all polls so far, but that referendum is still three months away. The decision we are invited to make next week involves ranking five alternative designs in our preferred order.
Those who have firmly decided they do not want a new flag face a dilemma of whether to vote in the first referendum. It they want to register their opinion at the outset, they may be inclined not to return their ballot paper this time. But when the non-vote is counted there will be no way of knowing how many want to keep the existing flag and how many do not care either way.
For that reason, some have urged opponents of change to write that view on the ballot paper, returning a "spoiled" vote in effect. But that runs a risk of a result that understates opposition to change since not many opponents are likely to send back a spoiled vote, and if some do so, the rest of the non-vote may be taken as those who do not care.
The better option for those who do not want a change of flag, is to take part in this referendum nevertheless. It is in their interests to do so. If the country is going to change the flag, opponents can at least ensure it might be the change they consider least bad.
The most foolish thing to do would be to try to poison the result by voting for the worst proposal. If a large number of opponents of change vote for the design they like least, it might well win this referendum. And if all enthusiasts for a change of flag unite behind it at the second referendum, it could become our new flag. So do not fool with this exercise. Vote honestly.
It is also important that this not be a vote for or against John Key. The fact that the current Prime Minister favours a new flag and has provided this opportunity should be immaterial to everyone's decision. Mr Key was not the first to advocate a change. If anyone deserves the credit in recent times it is Dave Currie, chef de mission of the New Zealand team at the 2004 Athens Olympics, who noted that the athletes preferred to fly a silver fern flag in the Olympic village. The following year a prominent businessman, the late Lloyd Morrison, formed a trust to promote a change of flag. This newspaper took up the cause in 2010, arguing the Union Jack on our flag had become an anachronism. Mr Key was a comparative latecomer, announcing this exercise last year. National supporters should not vote for change for his sake, just as political opponents should not let antagonism decide their vote. The referendum is not about him. It is a genuine opportunity that we are unlikely to get again. Do not waste it.