While most people want to retain MMP, a significant proportion do not feel informed enough to choose between the other options, the latest polling shows.
The Fairfax Media-Research International poll found 48.9 per cent of respondents wanted to keep the current Mixed Member Proportional voting system, while 33.2 per cent said no and 17.9 per cent didn't know.
The referendum to be held alongside the election will ask whether people want to keep MMP or change – and what alternative system they would prefer.
But the survey results suggest people do not feel comfortable choosing between relatively unknown options.
Asked which of four electoral systems they would want if MMP was scrapped, 33.2 per cent of respondents said they did not know enough to choose.
A further 9 per cent said they knew enough, but did not have a preference.
Victoria University political scientist Jon Johansson said Prime Minister John Key had the good sense to stay out of the referendum, but campaigners had to do more to inform voters.
"It's one thing supporting a horse but you ultimately have to lead it to your preferred water trough and they haven't been doing that.
The referendum was the result of an election promise by National rather than public demand.
In the poll, those who were younger, particularly under 35, tended to be more in favour of MMP, as did those who described themselves as struggling financially.
Those who intended to vote for the Labour Party and Greens also tended to be more likely to support keeping MMP.
More people aged over 60 supported FPP compared to younger respondents and men seemed more likely to support STV – 19.6 per cent compared to 9.3 per cent of women.
Campaign for Change spokesman Jordan Williams said the politicians had stacked things in favour of the status quo by not talking about the referendum.
Mr Williams said a promised independent review of MMP if it were kept could not be depended on, because implementation of its recommendations depended on politicians.
A second poll released today by the Keep MMP campaign found 25 per cent of people wanted to keep MMP as it is, 38 per cent wanted to keep it but make changes, and 27 per cent wanted to change to a different system.
A further 10 per cent were unsure.
The UMR Research poll also found 55 per cent of people supported MMP over FPP (35 per cent) and 10 per cent of respondents were unsure.
Keep MMP spokeswoman Sandra Grey said people must vote to retain MMP if they wanted to improve it.
"FPP has already been rejected by New Zealanders as an unfair system, and this poll shows that view has not changed."
The Fairfax Media-Research International poll questioned 1000 voters and had a margin of error of 3.1 per cent. The UMR questioned 750 people and had a margin of error of 3.6 per cent.
- Fairfax Media