Only the seat of Mt Gambier has emerged unchanged in a draft report released by the Electoral Districts Boundaries Commission on Friday.

The report moves about 240,000 voters into different seats.

Secretary David Gully said based on a projected enrolment of 1,241,999 at the next poll, the quota for each seat was set at 26,426.

"The boundaries commission was again faced with declining population in regional districts and with a number being outside of the allowable tolerance," Mr Gully said.

"This has resulted in significant proposed changes to the districts in the west and north of the state."

In one of the biggest changes, the large regional centre of Port Augusta has been divided between the seats of Giles and Stuart.

Submissions in response to the draft review will be taken until mid-September with changes to be finalised by November.

The latest review came after a major shake-up in 2016, which helped secure victory for the Liberal government in 2018.

That shifted almost 400,000 voters into different seats and nominally delivered four seats to the Liberals.

It was based on a so-called fairness clause designed to ensure the party which won the statewide popular vote would also win enough seats to form government.

In 2017, the then Labor government successfully scrapped the fairness clause in voting legislation and a move by the new government to bring it back failed in the parliament.

Labor told the boundaries commission it no longer had a mandate to ensure the objectives of the fairness principle were achieved.

Rather, Labor said the next redistribution should ensure every electorate has a similar number of voters, within a permissible tolerance, ensuring the one vote, one value principle.

The permissible margin was generally regarded as about 10 per cent.

By comparison, at the 2018 election, one Labor-held city seat had about 25 per cent more voters than one Liberal-held country seat.

But the Liberal Party argued the 2016 redistribution produced fair boundaries and said the commission should not change the methodology it applied at that time.

The Electoral Reform Society of South Australia also weighed into the debate, declaring the 2016 redistribution an unacceptable result and one that should not be allowed to happen again.

It backed scrapping of the fairness clause which it said would make the commission's work much easier.

Australian Associated Press