Data from the 2017 election suggests the Green Party don't have many soft-National voters in their ranks.

ANALYSIS: Data suggests the supposed "teal" section of National-leaning Green voters is tiny.

Both National leader Simon Bridges and failed Green Party leadership aspirant Vernon Tava have suggested there is a contingent of Green voters who are sick of the party's left-leaning stances on non-environmental issues, and refusal to consider going into Government with the National Party.

Tava is publicly mulling forming a party to pull these voters in, and is confident this party could reach five per cent.

But data from the New Zealand Election Study, a long-running scientific analysis of voter behaviour, suggests the overwhelming majority of current Green voters lean left.

The study consists of a survey of 3445 respondents following the election, who are asked a huge variety of questions. Their votes are validated and the results weighted to the wider voting public.

One of the questions asked of all these voters is whether they would prefer National or Labour lead the Government.

Fully 84.42 per cent of those who party voted Green said they would prefer Labour to lead the Government. Just under a tenth (8.47 per cent) picked National while 5.02 per cent said they didn't know and 2.09 per cent said they didn't want either party to lead.

Furthermore, these voters overwhelmingly rated themselves as left-of-centre politically - far more than Labour voters did.

Roughly three quarters (74.63 per cent) of Green voters rated themselves as left-of-centre on a ten point scale. Another fifth (20.1 per cent) either "didn't know" or put themselves in the centre. Just 5.26 per cent rated themselves as right of centre.

This compared to just over half (50.58 per cent) of Labour voters who rated themselves as left-of-centre.

New Zealand Election Study co-author and Victoria University political scientist Jack Vowles said he didn't think the Greens had much to fear.

"We looked at this fairly closely in our 2014 election book and for the vast majority of Green voters 'left' and environment are closely linked,' Vowles said.

"I think this is another case where (if successful) a party supported by National would be more likely to cannibalise its own support and the next step would be to look at centrist and centre-right National voters who have environmentalist leanings."

"TOP is the closest to what a blue-green party might have looked like and from other data it looks as if they drew equally from left and right, but hardly at all from 2014 Green voters. Most of the Green loss from 2014 to 2017 was to Labour - again confirming a left identification among Green-prone voters."

The Green Party won 6.27 per cent of the total party vote in 2017, meaning a small slice of their vote would not be enough to hit the five per cent threshold for entering Parliament.

It could however act as a "spoiler" to get the Green Party beneath the 5 per cent threshold and booted out of Parliament - which could benefit the National Party if their party vote remains higher than Labour's.

This is because the "wasted vote" - any vote that doesn't result in seats in Parliament - benefits the largest party the most.

JESS LEE/FAIRFAX NZ Potential Blue-Green party leader Vernon Tava.

In other words, if both NZ First and the Greens are voted out of Parliament next election and just Labour and National remain, National wouldn't need to win over any friendly parties for a coalition - the party would just need to be larger than Labour.

National could also gift Tava an electorate seat, as they do with the ACT Party in Epsom.

Another caveat concerns the size of the Green vote in 2017 - it was a lot smaller than in 2014, when the party won 10.7 per cent.

While the research suggests most of this vote moved to Labour, a more sizeable contingent of the larger Green vote at the 2014 election wanted National to lead the Government - a fifth (20.66 per cent).

That means there could be a slightly larger environmental-leaning vote floating around that would considering a National-led Government an okay outcome. But it is still seems to be far below the all-important five per cent.