Australia's Senate passed legislation earlier this week that paves the way for a landmark referendum later this year on whether to recognise Indigenous people in the constitution.

The Aboriginal and Torres Strait Islander people, who represent about 3.2 percent of Australia's nearly 26 million population, are not mentioned in the constitution.

Prime Minister Anthony Albanese has proposed adding an additional chapter to the constitution.

The new chapter will read as follows:

In recognition of Aboriginal and Torres Strait Islander peoples as the First Peoples of Australia:

1. There shall be a body, to be called the Aboriginal and Torres Strait Islander Voice;

2. The Aboriginal and Torres Strait Islander Voice may make representations to the Parliament and the Executive Government of the Commonwealth on matters relating to Aboriginal and Torres Strait Islander peoples;

3. The Parliament shall, subject to this Constitution, have power to make laws with respect to matters relating to the Aboriginal and Torres Strait Islander Voice, including its composition, functions, powers and procedures.

What is the proposed referendum question?

Albanese said last week the referendum question would be: "A Proposed Law: to alter the Constitution to recognise the First Peoples of Australia by establishing an Aboriginal and Torres Strait Islander Voice. Do you approve this proposed alteration?"

How does the referendum work?

The bill outlining the proposed changes passed its final parliamentary hurdle earlier this week. It will now be sent to the governor-general, the representative of the head of state King Charles, who issues a writ for a referendum.

The government will then announce a date for the referendum, expected to be between October and December.

How many votes are needed?

To change the constitution, the government must secure what is known as a double majority in the referendum.

That means more than 50 percent of voters must vote in favour nationally, plus a majority of voters in a majority of the states must back the change.

Votes of people living in the Australian Capital Territory (ACT), the Northern Territory regions, and any of Australia's external territories, count towards the national majority only. Poll turnout will be high as voting is compulsory.

How have past referendums fared?

There have been 44 proposals for constitutional change in 19 referendums, and only eight of these proposals have been approved.

In the last referendum in 1999, Australians voted against changing the constitution to establish the Commonwealth of Australia as a republic with the monarchy and governor-general being replaced by a president appointed by a two-thirds majority of members of parliament.