MMP's main weakness is stability and any changes could further damage that, the National Party says.



Party general manager Greg Hamilton told an Electoral Commission hearing on the review of MMP that it largely supported retaining the status quo.



MMP was an "imperfect system" but people had voted to keep it and it was important to maintain both the stability and proportionality of Parliament, he said.



"We don't need change for changes sake... In other words if it ain't broke don't fix it."



National wants the five per cent threshold for entering Parliament remain as well as retaining the ability for an MP who wins an electorate to bring in list MPs, such as occurred with the ACT Party in 2008.



If the five per cent threshold was reduced it would see more minor parties in Parliament, a greater cross bench and more likelihood of Governments having mid-term meltdowns.



The Labour Party however, believes reducing the threshold to four percent and doing away with the one seat rule, is a better way forward.



The rule achieved proportionality for a "some lucky players" such as the ACT Party but not New Zealand First in 2008, party general secretary Chris Flatt said.



Labour also wants political parties to retain control of their own lists.



Flatt said that could lead to even less representation of traditionally under represented groups.



The parties were submitting to the Electoral Commission's review panel which is looking at ways to improve MMP after a majority of New Zealanders voted to retain the system at the referendum held alongside the election last November.



Submissions will be heard in Wellington today and tomorrow. Other meetings are being held in Auckland and Christchurch.