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Another opinion poll has shown more voters prefer MMP to the old first-past-the-post system, giving campaigners who want to keep proportional representation confidence ahead of a referendum on the matter on November 26.
The poll showed 49 percent of the 503 respondents preferred MMP against 33 percent who preferred first-past-the-post, Campaign for MMP spokeswoman Sandra Grey said.
It was taken from June 7-15 and had a margin of error of 4.8 percent.
"We're taking calls and emails every day from members of the public about how they can get involved."
Its findings are in line with other recent polls.
In December, a TVNZ Colmar Brunton poll showed 50 percent support for MMP and in January a New Zealand Herald poll gave it 51 percent backing.
The referendum will be held at the same time as the general election.
Voters will be asked whether they want to retain MMP or change to another system. They will also be asked to choose a preferred alternative from several options, including first-past-the-post.
If a majority want change, a second referendum will be held alongside the 2014 general election when MMP will be run off against the most preferred alternative.
If a majority don't want to change, there won't be another referendum.