The Prime Minister has shrugged off Gina Rinehart's latest attack on the mining and carbon taxes, wondering "where's the news in that?"

Yesterday, Mrs Rinehart posted a 10-minute video on the Sydney Mining Club's website in which she said that Australia "simply can't afford" the two taxes.

The mining magnate said the evidence was "unarguable" that Australia was becoming too expensive to do export-oriented business.

"We are becoming a high-cost and high-risk nation for investment," Mrs Rinehart said.