National Party Leader John Key says Michael Cullen's puzzling comments on the tax treatment of charitable donations need clarification.

"Dr Cullen must be poised to re-write Peter Dunne's discussion document on charitable donations, because no-where is there any mention of a scrap on the cap for charitable donations.

"Charities deserve better than this double-speak from the Finance Minister.

"Dr Cullen appears to be re-writing history, and should say up front whether Labour's going to be copying National's policy in light of the announcement today."

Mr Key points out that two discussion documents and six years later, the charitable sector is still waiting for any meaningful announcement from Labour on what it is going to do for the charity groups working at the coalface.

There was a review of Tax and Charities in 2001. As a result the threshold for giving went up from $1500 to $1890, to adjust for inflation.

"No-one would describe that change as radical."

Mr Key also says that the current review (2006) has been undertaken because of the supply and confidence agreement with United Future and appears to have had little to do with Labour's advocacy.