The Coalition party room has approved the Prime Minister's plan for a National Energy Guarantee after a morning of debate, but former prime minister Tony Abbott has expressed strong concerns about it.

Key points: Party room debated the National Energy Guarantee for almost two-and-a-half hours

Party room debated the National Energy Guarantee for almost two-and-a-half hours Some MPs including Tony Abbott, George Christensen and Eric Abetz have reserved their right to vote against it

Some MPs including Tony Abbott, George Christensen and Eric Abetz have reserved their right to vote against it Phone hook-up scheduled in which states will be asked to agree to the next step

The NEG is aimed at cutting emissions in the electricity sector by 26 per cent, as well as putting downward pressure on energy bills and ensuring a reliable power supply by forcing power companies to buy some electricity from sources like coal, gas, batteries or pumped hydro.

PM Malcolm Turnbull said it meant the nation was "one step closer to cheaper and more reliable energy".

The meeting lasted for almost two-and-a-half hours and has been described as "testy".

Mr Abbott has previously spoken against the plan in relation to its commitment to ensuring Australia meets emissions targets agreed to in the Paris climate change accord.

He and colleagues — Andrew Hastie, Andrew Gee, George Christensen and Eric Abetz — have reserved their position on the legislation, meaning they could cross the floor to vote against it.

Barnaby Joyce is also pushing for more guarantees that the NEG would bring down prices before he supports the plan and Nationals Senator Barry O'Sullivan has major concerns.

After the meeting, Mr Abbott issued a statement that said most of the explanations of how the NEG "might theoretically get prices down" sounded "like merchant bankers' gobbledegook".

He acknowledged that there was support for the plan but said much of it was conditional.

"Yes there were lots of pleas for unity, but as one MP said: 'We've got to be loyal to our electorates and to party members too and not show the unity of lemmings.'," Mr Abbott said.

He said at least a dozen members of the Coalition expressed serious concerns about the NEG or the Paris targets, although it is understood the number of dissidents is disputed by others in the party room.

George Christensen, Andrew Hastie, Tony Abbott and Eric Abetz are among those with misgivings. ( ABC/AAP )

Other concerns raised about detail, no price target

Senator Abetz is understood to be concerned that only a two-page document was provided to explain the detail of the way the NEG would work.

Liberal backbencher Tony Pasin said he could not support a NEG without a price target.

He said the NEG focused on reliability and emissions reduction rather than the cost of electricity.

Mr Pasin described the assumptions in the NEG modelling about the price of power falling as "brave" and said he wanted to see a target or Government expectation that prices would fall.

Energy Minister Josh Frydenberg said the Government had a "laser-like" focus on reducing power bills.

Mr Turnbull said the concerns expressed in the party room were about cost and pledged that "everything we are doing is seeking to bring down energy prices".

Twenty-six members of the Coalition spoke in favour of the plan during this morning's meeting and the majority of the Coalition party room has endorsed the plan, although the ABC has been told some did so with misgivings.

Mr Turnbull is now pressuring Labor to agree to back the NEG.

"The Labor Party has to decide whether they want to support cheaper and more reliable electricity," he said.

So far the Opposition has not announced a final position on the energy plan, but it has argued that the target of cutting emissions by 26 per cent is too weak.

Mr Turnbull said Labor should back the NEG with the current target and it could argue for a higher target at the next election.

Labor's Energy and Climate Change spokesman Mark Butler has not outlined Labor's final view but he is increasingly critical of the NEG.

"Today Malcolm Turnbull presented an energy plan that will see not a single renewable energy project built for 10 years, will see the rates of rooftop solar on Australian houses halve, and will channel potentially billions of taxpayer dollars into building new coal-fired power stations that the industry itself says are un-investable," Mr Butler said.

Greens leader Richard Di Natale said Mr Butler was right "when he said that this was a dud of a policy".

"We don't get more renewables in the system, we lock in coal, the targets aren't based on science," Senator Di Natale said.

He criticised Labor for attacking the NEG but not saying whether it would oppose the plan.

State governments will now decide whether to sign on to the plan.