Support is slightly greater for a Government staying in power for three years - but a referendum is possible.

Voters are almost evenly split on whether the parliamentary term should be extended from three to four years in the latest poll - a narrow margin believe it should stay at three years despite general agreement among politicians that a move to four is warranted.

Just over half of those asked in a Herald-DigiPoll survey said they believed the three-year term should stay, while 48 per cent believed it should increase to four years.

The issue is being canvassed as part of the Government's Constitutional Review and last month both Prime Minister John Key and Labour leader David Shearer voiced support for a four-year term with a fixed election date. Supporters of it have called for a referendum in the 2014 election so any changes can be made from 2017.

The independent panel charged with advising on the Constitutional Review began a six-month period of consultation last month and will then make its recommendations to the Government.


Mr Key has said any such change would be made only if there was sufficient public support, likely to be determined through a referendum.

The poll indicates that public opinion has shifted since a four-year term was rejected in two referenda in 1968 and 1990 - in both morethan two-thirds of voters opted to stay with the three-year term.

The Herald-DigiPoll result was closer than a One News Colmar Brunton poll taken in February which showed 56 per cent supported a change to four years.

Electoral law specialist Graeme Edgeler said he was yet to be convinced that a shift to a four-year term was needed or desirable. He said New Zealand's system lacked the checks on governments that other countries had, such as an Upper House, an entrenched Bill of Rights, or strong state governments.

"We get a Government and they can do pretty much what they like for three years. We currently have control over politicians every three years. If we go to four, that's less democracy."

He did not agree with the argument that three years was not enough time to bed in significant reforms, saying it had not stopped previous reforms ranging from income tax laws to ACC.

David Farrar, a National-aligned blogger, supported a move to four years, saying three years was not enough time in which to assess whether new policies were working. He expected it would result in more one-term Governments - something that has happened only twice so far in New Zealand's political history.

"People do feel three years is not long enough to judge. With a four-year term, more Governments might get chucked out after one term because people would say, 'It's been four years, we should have seen some impact."'


The Herald-Digipoll survey was of 750 eligible voters and has a margin of error of plus or minus 3.6 per cent.