Wellington, Sept 14 NZPA - Prime Minister John Key isn't impressed with Labour's pledge to stop power companies fleecing consumers and says the previous government raked in dividends worth $3.1 billion.

Labour leader Phil Goff said yesterday a future government wouldn't demand excessive dividends from state-owned power companies, and Labour had been wrong not to deal with soaring prices while it held office.

Mr Key said today power prices had risen just 1.93 percent since National had been in power, mainly because of the tough stance ministers had taken with the state-owned companies.

"From November 1999 to November 2008 (while Labour was in power) retail prices rose 67 percent," he said.

"In my view Labour is saying one thing in opposition and did a completely different thing in government."

Mr Key said Labour's promise meant it would have to challenge the structure of state-owned companies, which were supposed to act in a way that was consistent with commercial operation.

"In effect, they would be talking about price fixing of a sort, which might be in breach of the Commerce Act."

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