More than a-third of voters say Nicky Hager's book Dirty Politics has affected their decision on who to vote for in varying degrees.

But the majority of people who've filled out the Vote Compass survey say it's had no effect at all.

More than 206,000 people have taken part in the survey hosted by ONE News, which calculates how the policies of different parties line up with your own personal views.

The results to the questions on Nicky Hager's book are based on 13,913 respondents to Vote Compass from last Thursday to today.

Hager used hacked emails to allege in his book that National Party figures were working with Cameron Slater to smear political opponents on his Whale Oil website.

Asked how much truth they think there is to the claims made by Nicky Hager in the book , 9% of the respondents said "none", 24% said "little" while another 24% said "some" and 25% thought there was "a lot" of truth to the claims. Eighteen per cent didn't know.

"I just think where there's smoke there's fire. There's probably something in it that's been embellished a wee bit," Jim Lawrence, a Kaiapoi Voter told ONE News.

Masterton Voter Pat Everitt said: "It's got me a lot more disappointed because it seems to cloud so many of the issues when they are stirring up the mud."

Professor Jack Vowles of Victoria University says the book's impact could increase.


"The longer something like this goes on of course, then the more effect it might have, particularly depending on more stuff coming out," he said.

To the question "How much of an effect has Nicky Hager's new book, Dirty Politics, had on your decision about who to vote for?", 56% of the Vote Compass respondents replied "none".

But 15% said it has had "little" effect, 11% said "some" effect, and 10% said it had "a lot" of effect on their voting decision. That's a total of 36% saying the book has affected their voting decision. Eight percent didn't know.

"It's somewhat more than what someone might expect in some respects because from what we know about political psychology, people tend to resist new information that's inconsistent with what they thought before," Professor Vowles said.

The findings are based on 13,913 respondents to Vote Compass from August 21-25. Though Vote Compass is not a poll, respondent data are weighted using the latest census data to approximate a representative sample of the New Zealand population.

Take part in Vote Compass atonenews.conz/votecompass

Once you've finished, Vote Compass compares your answers with the policy positions of the parties then displays your position on a grid, showing where you stand in the overall political landscape. If you wish, you can choose to share your results page on social media.

Learn more about Vote Compass here.