South Australians could be headed to their first referendum in almost 25 years to vote on dramatic changes to the power of the Upper House.

The Government has proposed legislation that would permit a double dissolution election if there are persistent disagreements between the Upper and Lower House.

Another bill sets out that if the Legislative Council rejects the budget - known as the Appropriation Bill - or fails to pass it within one month, it will be taken that the bill has passed both houses of Parliament.

Automatic approval would also apply if the Upper House amended the legislation but the House of Assembly did not agree with the changes.

If the two bills pass, they would have to be supported at a referendum at the next election in 2018 to come into effect.

South Australians last went to a referendum in 1991.

In 2009, then premier Mike Rann backed away from plans to hold a referendum on abolishing the Legislative Council because the public would not have supported the move.

Attorney-General John Rau said the double dissolution proposal to resolve legislative deadlocks is modelled on the Federal Parliament.

"The new deadlock mechanism makes possible a double dissolution election and a joint sitting of Parliament to resolve any impasse between the houses," Mr Rau said.

"This will only be an option in the event of an ongoing and persistent deadlock between the houses of Parliament."

In the Australian Constitution the Government can request the governor-general to dissolve both houses and call a full election.

If after the election, the legislation that triggered the double dissolution is still not passed by the two houses, then a joint sitting of the two houses can be called to vote on the legislation.

In its report on the legislation to ensure swift passage of the budget, the Government states the Legislative Council today has "more power in relation to the annual appropriation bill than was originally intended".

"There is a risk that the legislative council could misuse that power and for example unacceptably delay the annual Appropriation Bill, and in doing so disrupt the machinery of government," the report stated.

Government attempting to avoid scrutiny: MP

Family First MLC Robert Brokenshire said the proposed changes were concerning.

"It's clear that this Labor Government doesn't like the scrutiny it gets from the Legislative Council," Mr Brokenshire said.

"It would rather have a dictatorial opportunity of government.

"The South Australian community reject that and that's why they're actually putting more small parties and independents into the Legislative Council," he said.

Mr Rau has repeatedly expressed frustration with the Legislative Council, which has blocked a number of key Government bills.

One of those was the controversial car park tax.

Its defeat blew a $120 million hole in the budget.

"The Legislative Council does not block supply. It gets on with the job as quickly as it can," Mr Brokenshire said.

"But you know when it comes to something like a car parking tax, the Government didn't like the fact that the Legislative Council stopped that but guess what, the community didn't want the car parking tax so this is a Government that is trying to set up a dictatorship."

The Opposition said it was considering the legislation but was concerned about watering down the review powers of the Upper House.

"The Liberal Party's highly unlikely to be supporting anything which is going to destroy the power of the Legislative Council," Opposition treasury spokesperson Rob Lucas said.

Mr Rau said he was also introducing changes to the Upper House voting system to stop micro parties being elected through preference deals.

"This system avoids the distortion of outcomes that can result from preference deals," he said.

The model would not allow for voters to cast their own preferences.

"This new Government scheme hasn't been tried anywhere in Australia and I don't think it's the way we should be going," Greens MLC Mark Parnell said.

The model would have prevented federal senator Nick Xenophon from winning his seat in the SA Upper House in 1997 prior to being elected to the federal Senate in 2007.