A postal form for the same-sex marriage survey
A postal form for the same-sex marriage survey (Image: AAP/Peter Rae)

In the lead-up to the expected referendum on whether to create an Indigenous Voice to Parliament, most polling has found that support for a Yes vote is falling, leading to increasing doubt about whether the referendum will pass. 

In 2017, after the polling failures for Donald Trump’s election chances and Brexit, there were also concerns that the No case might succeed in the same-sex marriage postal survey. However, the polling histories of the Voice and the postal survey are completely different.

Polls on the Voice use various methods to deal with voters still unsure about how they will vote. Some