Opposition Leader Bill Shorten has called Prime Minister Scott Morrison a “coal-wielding, climate-denying cave-dweller” and said attacks on Labor’s climate change policy are “malicious and stupid”.

In some of his strongest comments to date on Labor’s emission reduction scheme, Mr Shorten said “it’s a stupid position not to take action (on climate change)” and “there will never be enough figures to satisfy the climate sceptics”.

Mr Shorten has come under fire from the Coalition for claiming his 45 per cent emissions reduction target would have no cost to the economy.

The Australian has reported that if introduced businesses could be forced to spend $25 billion on international carryover credits by 2030.

“The $25 billion figure is a lie. It’s using... You can make any number work for you if you pump in the assumptions you want to,” Mr Shorten said at his press conference in Darwin this morning.

“When it comes to carbon pollution reduction, our strategy is the lowest cost abatement using a combination of international tools and domestic tools and might I also say plenty of incentives. Did you know that if we properly invest in renewables, there would be tens of thousands of new jobs?

“The News Corp climate change deniers, and their allies, the Prime Minister - a coal-wielding, climate-denying cave-dweller on this issue - they all say, ‘Look at the cost,’ but never mention the cost of extreme weather events, do they?

“You all recognise a scare campaign when you see one. I’ll give you the numbers — 50,000 more jobs in renewables if we go down our path.

“I’ll give you another number — $18 billion, the cost of natural disasters.”

Climate change and energy policy is emerging as one of the central issues of the campaign so far, with the ALP also attacking Mr Morrison for suggesting new nuclear power stations could be allowed in Australia.

When asked on radio this morning why nuclear power was not on the agenda, Mr Morrison said: “Well it’s not not on the agenda and wherever it can come from is fine but it’s got to be self-sustaining.”

NSW ALP MP Tony Burke said: “ Nuclear power is against the law in Australia. It is extraordinary that Scott Morrison is now contemplating changing the law to allow nuclear power stations in Australia.”