Labour's being accused of politicking with plans to draft its own changes to the MMP system after snubbing an invite to discuss potential changes with the government.
The Electoral Commission has recommended lowering the party vote threshold to four per cent from five per cent for a party to get into parliament, abolishing the "one-seat rule" that exempts a party from the threshold if it wins an electorate seat, and abolishing the provision for overhang seats.
The commission also advises fixing the percentage ratio of electorate to list seats at 60:40.
Labour leader David Shearer says he does not believe the government will follow up on the recommendations, so his party will draft a private member's bill of its own to implement the changes.
Justice Minister Judith Collins scorned the plan, saying she would prefer a "consensus style of electoral reform", rather than "shoving things through like [Labour] did with the Electoral Finance Act".
She says she gave Mr Shearer a copy of the commission's report on Thursday and invited him to discuss it with him, but hadn't heard back "other than by press release" before Labour's announcement on Tuesday.
"Actually, I don't think that smacks of someone who's very genuine," Ms Collins said.
"He needs to get some better advice than he's getting now."
She says she is hopeful of reaching cross-party consensus on any changes, despite both ACT and United Future wanting to keep the one-seat rule that delivered them to parliament.
"My view is we should have as much consensus as possible ... I would think we'd want a substantial majority for any changes."
The government would have more than a majority of support for the changes with the backing of Labour and the Greens, but it also relies on ACT and United Future for support.
It's expected the Electoral Act will be changed before the next election in 2014.