Half of New Zealand's electoral boundaries are expected to change, and a new electorate is proposed for South Auckland.

The Representation Commission released its report on the proposed boundaries and names of electorates for the next two elections today.

It suggested the number of electorates increase by one to 72 because of population growth.

Changes are proposed to 35 of the 71 current electorates, with the biggest moves in Auckland, Christchurch, Otago and Southland.

In the country's biggest city, a new electorate is being proposed, called Flat Bush.

The new electorate will have an overall population of 66,306 and draws in people from the current electorates of Manurewa, Papakura and Hunua.

Down south, boundary changes are slated for Selwyn because of rapid population growth.

The number of Māori electorates remains at seven, however adjustments are proposed for Tamaki Makaurau to cover a bigger area around Te Atatu South.

Meanwhile, a minor change is proposed between Ikaroa-Rāwhiti and Te Tai Tonga in Naenae.

Name changes are being proposed as well.

That includes changing Rodney to Whangaparaoa, Hunua to Port Waikato, Rimutaka to Remutaka and Port Hills to Banks Peninsula.

The public will get their change to have a say over the coming months, along with public hearings, before boundaries are finalised in April.

Commission chair Judge Craig Thompson said change was needed for the 2020 election.

"The important factor is that each electorate needs to have approximately the same number of people in it - so that everybody has an equal representation in Parliament," he said.

"Where possible, the existing boundaries have been retained to minimise the number of people who are affected."

Judge Thompson has confidence in the population figures given the census debacle at Stats NZ.

"We have been well assured by the government statistician and by the report of the review panel into the census results that the figures that we have been given are reliable ... nobody has argued to the contrary," he added.