Prime Minister Malcolm Turnbull has flagged the government financing new power plants, even those fuelled by so-called clean coal, as he launched a fresh assault on power prices that included confirmation of export restrictions on gas to ensure domestic supply.

The government will also legislate to abolish limited merits reviews, an appeals process used by power utilities to charge high prices. The abolition of the mechanism, which the government said had added $6.5 billion to power bills over recent years, will pass Parliament after the Greens indicated their immediate support.