The fairness of MMP has been questioned today in the first of the public hearings in a review of the voting system.
The Electoral Commission is conducting the review following a referendum last year in which New Zealanders voted to keep the system.
Among the more controversial aspects of MMP that is being discussed are the rules around thresholds for entry into Parliament.
At present, a party can gain representation by either getting 5 per cent of the party vote, or by having an MP win an electorate seat.
If a person is elected to a seat, they can bring other list members into Parliament based on the level of party votes - regardless of whether the party has crossed the 5 per cent threshold.
Several political parties spoke about thresholds in their submissions today, expressing mixed opinions about what the ideal situation would be.
National's Greg Hamilton said his party's preference was to retain the status quo because it felt it provided the right balance between proportionality in Parliament and the ability to provide a stable government.
Mr Hamilton said the one-seat threshold was important for maintaining a representative mix and removing it would be "unworkable".
"Without the one seat threshold, there would be significantly greater 'wasted vote', Parliament would have less minor party representation, and would be much less proportional."
In contrast, Labour Party general secretary Chris Flatt argued that the current system was unfair, and the one-seat rule should be abolished.
Mr Flatt held up the Epsom and Ohariu electorates as examples of where the rule meant some voters had significantly more power over Parliament's make up.
"Labour has no objection to an individual electorate being represented by an MP from a small party, but does not believe that that achievement should secure the right of list candidates from that party to be elected, when list candidates from a party with identical levels of broad public support are not elected."
While National argued against the prospect of lowering the party vote threshold, Labour said it should be lowered to 4 per cent.
The Electoral Commission is expected to deliver its final report to the Government by October 31.