The Turnbull government is offering some wriggle room on the most contentious point of its signature energy guarantee as state and territory ministers look toward a final deal.
Plans for the National Energy Guarantee would lock in a 26 per cent emissions reduction target for the electricity sector until 2030.
The goal has faced heavy criticism for not being aspirational enough, particularly given the Energy Security Board which designed the guarantee has forecast a 24 per cent reduction by 2020/21.
Federal Labor has vowed to ratchet up the target if they win the next election, and now the government appears to be offering the opportunity to do the same.
AAP has confirmed a review of the target in 2024/25 could allow the target to be adjusted in 2025.
Previously the guarantee allowed five-yearly reviews to set the next target for 2030 to 2035.
The target has been a sticking point for some states in earlier discussions, as well as for energy and climate groups.
There have been calls for a more ambitious target to reduce the pressure that a 26 per cent goal would place on other sectors, including agriculture and transport, where emissions reduction is more difficult.
Australia has committed to reducing 2005 level emissions by 26-28 per cent by 2030.
A leaked copy of advice to states and territories by the ESB addresses those concerns by saying "it is possible that higher emissions reduction targets may be set in future by the Australian government".
Treasurer Scott Morrison said higher targets were not the way to go.
"If you go down the Labor path, which sees higher renewable energy targets, higher emissions reductions targets, that can only mean higher electricity prices," he said in Sydney.
The ESB advice has revealed the latest iteration of the guarantee could save the average east coast household $550 a year on their energy bills in the decade from 2020, relative to 2017/18.
This is $150 a year more than previously forecast for the same period.
"The continued connection of additional renewable generation projects to the NEM (national energy market) in coming years is projected to see prices fall from today's elevated levels," the 39-page report says.
Energy ministers will meet on August 10 when the government is hoping to get the go-ahead for legislation to pass parliament before the end of the year.
But Labor leader Bill Shorten criticised Mr Turnbull's priorities in seeking state and territory support for the deal when a number of coalition backbenchers don't support it.
Mr Shorten has called for a commitment from the government for a 50 per cent renewable energy target.
"(Malcolm Turnbull) knows if we have a commitment to 50 per cent renewable energy that'll unlock a wave of new investment, which is the very thing we need to put down pressure on power prices," he said.
