Tony Abbott's past as a climate change "weather vane" has come back to haunt him - again.

The Opposition Leader has been shown spruiking a carbon tax in an old interview that was aired on Q&A on ABC Television yesterday.

Caught out ... Tony Abbott. Credit:Sahlan Hayes

"If you want to put a price on carbon, why not just do it with a simple tax?" Mr Abbott argues.

"Why not ask electricity consumers to pay more, then at the end of the year you can take your invoices to the Tax Office and get a rebate?