Coalition MP breaks ranks on RET

A coalition MP has broken ranks on a bipartisan renewable energy target deal, threatening to vote against legislation before parliament.

Nationals MP Keith Pitt said the draft laws paring back the target from 41,000 gigawatt hours to 33,000 would only increase the cost of electricity for those who could least afford it, and slug taxpayers billions of dollars to subsidise private enterprise.

"And come 2020, environmentalists will have little to show for it other than a warm and fuzzy feeling," he told the lower house on Tuesday.

Another coalition backbencher also voiced concern with the draft laws, saying the target simply won't work.

Liberal Craig Kelly said the legislation, which requires 20 per cent of Australia's energy to come from renewables by 2020, would lead the nation backwards in terms of productivity.

He questioned how building 2,000 wind turbines would reduce the impact of climate change.

"It is little different from those in primitive societies that believed that we can change the weather by throwing 2,000 virgins down a volcano," Mr Kelly said.

The costs of investing in solar panels would outweigh the benefits, he said.

"The investment will see $9 billion of our nation's limited and precious resources - excuse the language - simply pissed up against the window."

But he didn't say whether he would join Mr Pitt in opposing the bill.