Thousands of Australians took to the streets in cities and towns across the country on Sunday to back the Yes23 campaign, a nationwide “day of action” to rally support for the proposal to recognise the country’s Indigenous people in the constitution.

The proposed referendum, which is expected to take place between October and December, seeks to establish an advisory body – the Indigenous Voice to Parliament – to give Aboriginal and Torres Strait Islander people a direct say in policies that affect them.

The Prime Minister Anthony Albanese’s centre-left Labor government backs the change, while the opposition Liberal-National conservatives urge a “No” vote. Yes23, the group behind more than 25 rallies nationwide, said the crowd in Sydney was estimated at around 3,000 people, with a total of up to 25,000 people participating in total.

Despite the enthusiasm shown by the public in the streets, recent polls have suggested that support for the referendum is waning. A poll last month showed “No” ahead for the first time, 51 percent to 49 percent. However, the Yes23 campaign director Rachel Perkins believes the dip in polls does not reflect the reality on the ground.

Opponents of the referendum, including some Indigenous people, have argued that the proposal lacks detail and will divide Australians. Critics are also saying that other issues such as education, health, safety and domestic violence within Indigenous communities should be addressed and prioritized instead.

To be successful, the referendum must secure a double majority: more than 50 percent of voters nationwide, and a majority of voters in at least four of the six states. This is no easy task, as in the past, out of 44 proposals for constitutional change in 19 referendums, only eight have passed.

The stakes are high for the upcoming referendum. But with the strong public support shown in the streets on Sunday, it is clear that the momentum behind the campaign is growing and Australians will be awaiting the result with anticipation.