Swan a very nasty politician: Barnett

UPDATE 12.30pm: Premier Colin Barnett says he has a hard time liking Federal Treasurer Wayne Swan, labelling him "a very nasty politician".

The Liberal leader has locked horns with Mr Swan previously over his threats to cut GST revenue or infrastructure funding if States increase mining royalties.

Mr Barnett told Fairfax radio today that he didn't take kindly to Mr Swan's threats.

"I think he's a very nasty politician," Mr Barnett said.

"He gets very personal.

"I find it difficult to like Wayne Swan."

A spokesman for Mr Swan said the WA Premier could "focus on personal abuse", but the Treasurer's focus was elsewhere.

"We'll keep focusing on the economic management that has seen Australia today become the 12th largest economy in the world, up three places under this Labor government, with low unemployment and interest rates less than half the level we inherited," Mr Swan said.