The star has teamed up with Cate Blanchett for an advertising campaign urging voters Down Under to back the government's planned carbon tax, which would be levied on companies contributing to pollution.
Many fear the tax will be passed along to families already struggling in the tough economic climate through a series of price rises, and National Party Senate Leader Barnaby Joyce, who opposes the tax, blasted Blanchett for failing to understand the impact it will have on hard-up Australians.
But Caton has defended the Elizabeth star and explained his decision to front the scheme's campaign.
He tells Australia's Sunrise show, "I think that criteria is very unfair and is below the belt. She (Blanchett) is a very passionate person and Cate has had solar panels on her house for years... it's obviously something she really believes in.
"The decision we make today will be what our children and grandchildren live with in the future. People who are worried about this tax, 50 per cent of the tax is going back to people who are disadvantaged by it.''