If voters choose next year to change from the current MMP electoral system, a majority want the new system in place before the 2014 election, according to an opinion poll.

The survey, released yesterday, suggested people are likely to vote in favour of at least having the opportunity to chose between retaining MMP and other options. The referendum will coincide with the 2011 general election.

If the country opts then for a rethink, another referendum - to choose between MMP and the preferred alternative - will be held with the 2014 election.

However, a second round of findings from the Business Council for Sustainable Development's survey reveals strong support for bringing forward the second referendum in order to decide the issue in time for any successor to MMP to be in place for the 2014 election.

The nationwide survey of 2261 people found 56 per cent in favour of fast-tracking the second referendum, while just 18 per cent wanted to hold to the current timetable.

However, Associate Professor Andrew Geddis, an Otago University electoral law expert, said rushing the process could result in "a mess".

Cabinet papers issued when the timetable was considered showed the plan to hold the two referendums in conjunction with consecutive elections was chosen because it was the most cost-effective option and it escaped the risk of a mid-term referendum failing to secure high voter participation.

"That would be the nightmare scenario," Professor Geddis said.

"You have this great referendum to decide the electoral process that's going to be used for future generations and you only get 50 per cent of the population voting, as opposed to the 80 per cent turnout in an election."

The MMP timetable:
* 2011 election - referendum on whether to keep MMP, and to choose possible alternative.

* 2014 election - referendum to choose between MMP and the preferred alternative.