Canberra, Oct 14 : Polling booths across Australia opened on Saturday for the country's first ever referendum in the 21st century, with voters to decide on whether or not to establish an Indigenous Voice to Parliament. Millions of Australians will on Saturday vote "yes" or "no" on the proposal to alter the constitution to recognise the First Peoples of Australia by establishing the voice, which would advise the federal Parliament on all issues affecting Aboriginal and Torres Strait Islander people, reports Xinhua news agency. In order for the constitution to be changed, the "yes" vote must secure a double majority, meaning that more than 50 per cent voters nationally, as well as a majority in at least four out of Australia's six states, must vote in favor. In a final pitch to voters on Friday, Prime Minister Anthony Albanese said the referendum was an opportunity for Australia to "do better". "We have an opportunity for Australians to do better. To do better to show respect for the first Australians, but to do something for ourselves, as well, because we will feel better. We will feel better about ourselves on Sunday with a Yes vote," he said at a press conference in South Australia. The Australian Electoral Commission (AEC) personnel will start counting the votes as they close at 6 p.m. on Saturday. According to the AEC, voting is mandatory for Australians aged 18 and over who are registered on the electoral roll (about 17.7 million people), while by the close of business on Wednesday, approximately four million people have voted at an early voting centre. The Voice to Parliament was recommended by a historic document in 2017 called the Uluru Statement from the Heart. Drafted by more than 250 Indigenous leaders, the statement is considered the best -- though not unanimous -- call to action for reforms on issues affecting First Nations Australians. It also lays out a longer process of treaty-making and truth-telling. The issue, however has been a fierce topic of debate for years as country has not had a successful referendum in almost 50 years. If approved, the vote would recognise Aboriginal and Torres Strait Islander people in the country's constitution, and establish a permanent body for them to give advice on laws. The composition, functions and powers of the body, whose advice would not be binding, would then be designed and debated by Parliament. /IANS