Australia currently spends around 2.3 per cent of our GDP on the aged pension, but that figure is falling (gross domestic product (GDP) is the value of all the goods and services created in a year).

"It'll go down to around 2 per cent by 2060," says Ms Delahunty.

"This is against a backdrop of an aging population with increased health needs.

"It's bucking the trend internationally. Most OECD countries are [spending] 9 per cent and growing, and they will be above 10 per cent by 2060."