None of the alternative national flags are likely to pose a challenge to the existing flag in upcoming referenda, a new poll shows.
The survey by UMR Research revealed that Kyle Lockwood's two silver fern flags were the most popular choices out of the alternative designs.
An alternative flag will be chosen from five designs through a single transferable vote system next month, in which voters list their preferences from one to five. If no flag receives more than 50 per cent of the first preferences, the least popular flags will be eliminated until one design wins half of the votes.
In the UMR survey, 36 per cent of respondents picked Mr Lockwood's Silver Fern (Red, White and Blue) as their first preference.
Mr Lockwood's Silver Fern (Black, White and Blue) won 33 per cent of the vote, ahead of Aaron Dustin's Red Peak on 18 per cent, Alofi Kanter's Silver Fern (Black and White) on 7 per cent, and Andrew Fyfe's Koru on 6 per cent.
Once the single transferable vote method was applied, the red, white and blue silver fern won ahead of the black, white and blue silver fern, but the result was within the margin of error.
In a head-to-head vote, the existing national flag was much more popular than each of the alternative flags.
The most popular alternative in the head-to-head vote was Mr Lockwood's black and blue fern, which won 35 per cent of the vote.
The alternative designs were chosen by a Flag Consideration Panel from a shortlist of 10,300. Four designs were originally chosen by the panel before supporters of Red Peak successfully lobbied Parliament to include it on the list.
The poll of 1000 people had a margin of error of 3.1 per cent.
Prime Minister John Key said this afternoon that changing the flag was always going to be a difficult task.
But he said that once an alternative flag had been chosen in the first referendum people's thinking would "crystallise" around a new design.
"I think you'll see a fair bit of activity around imagery and what a new flag might look like and a more intensified debate.
"Doesn't mean it's going to be an easy thing to change the flag. But ... I think it's a long way to the finishing line before we see how New Zealanders vote."