A new poll on the flag shows the current flag has almost twice as much support as the alternative flag although support appears to have softened slightly.
The poll taken by UMR Research shows 59 per cent want to keep the current flag while 32 per cent want to change. About 9 per cent were still undecided.
The poll of 750 voters was taken in the last week of February, just before ballot papers were sent out on Thursday. UMR Research also does polling for the Labour Party.
In the last UMR poll in January, 65 per cent said they would vote for the current flag while 35 per cent would vote for change.
The issue appeared to be split along political party lines -- National voters were evenly split on it with 45 per cent voting each way. Almost three quarters of Labour voters said they wanted to keep the current flag and 19 per cent favoured change.
Almost 90 per cent said they were almost certain or very likely to vote.
More men than women favoured change -- 36 per cent of men said they wanted change compared to 29 per cent of women.
UMR's earlier poll in January showed a significant chunk of voters -- one in five -- wanted a change but were voting to keep the current flag because they did not like the design of the alternative.
About 80 per cent of that same group were also likely to see a vote against change as a way to "send a message to John Key".
The poll of 750 voters was taken from February 25-29 and has a margin of error of +/- 3.6 per cent.