Legislation to get a referendum on the MMP voting system at the 2011 general election had unanimous support in its first reading in Parliament on Thursday.
The bill will now be sent to the specially-formed Electoral Legislation Committee for consideration.
All parliamentary parties are represented on the committee.
The bill sets out two questions to be asked of voters - whether they wish to retain the Mixed Member Proportional voting system and what alternative system they would prefer.
The options are: MMP, First-Past-the Post, Single Transferrable Vote and the Supplementary Member system.
If there is a vote for change, the Government will be committed to holding a second, binding referendum at the general election in 2014.