Two days before the referendum, voter opinion still appears to be well on the side of MMP.
The latest Herald-DigiPoll survey shows 54.4 per cent of voters want to keep the current electoral system, and 35 per cent want to change.
The results are in line with previous polls, which have consistently shown a preference for keeping MMP.
In tomorrow's referendum voters will be asked whether they want to keep MMP, and to choose their preference among four replacement electoral systems.
Of the alternative systems, first past the post received the most support in the poll, with 29.9 per cent of respondents saying they would vote for it. Single transferable vote came in second on 17.2 per cent, supplementary member was third on 13 per cent, and preferential voting was last, on 11.4 per cent.
Of the respondents, 4.4 per cent said they would not choose an alternative system.
Only 13.3 per cent of people said they fully understood how each of the alternative systems worked, 64.2 per cent mostly or partly understood, 15.2 per cent understood only a little and 7 per cent said they had no understanding.
If more than 50 per cent of people vote to ditch MMP, Parliament will decide whether to hold another referendum in 2014 to choose between MMP and the alternative voting system that gets the most support.
If people vote to retain MMP, the Electoral Commission will review the system next year to consider if changes should be made to how it works. The review would be reported back to the Government by October 31.
As well as the proportionality of the system, the review will consider MMP's more contentious aspects, such as the threshold parties must achieve to win a seat, the order of candidates on a party list, and dual candidacy.
The dual candidacy rule allows candidates to stand for an electorate and on a party list, meaning that in some cases an electorate MP can be rejected by local constituency but get back into Parliament on the list.
Another aspect of MMP that has drawn wide opposition is the one-seat exception, which allows a minor MP who wins an electorate to bring in "coat-tail" MPs from their party list, even if their party does not reach the 5 per cent party vote threshold otherwise needed to gain parliamentary representation.
Vote for Change spokesman Jordan Williams, who has been leading the anti-MMP charge, said he did not trust politicians to make the changes people wanted because systems such as dual candidacy helped them into Parliament.
"The review will be independent, but the problem is it ultimately ends up in the hands of whoever is Minister for Justice, to carry through on any of the recommendations."
However, Keep MMP spokeswoman Sandra Grey dismissed the suggestion that MPs would reject changes based on their own agenda, saying politicians had to keep the public happy.
"They are reliant on us for getting into Parliament, and if the public very clearly indicate what they want through the review process, politicians are going to have to listen to that."