Under pressure over his energy plan, Malcolm Turnbull is promising to use a "big stick" on power companies that fail to deliver on cheaper prices.
The prime minister says prices will come down through his signature energy policy and the government will set a "price expectation" confirming the most anyone should pay.
Power companies that don't pass on savings will be put on notice by the competition watchdog and face the "toughest penalties" if they don't turn things around, Mr Turnbull said in a video on Facebook.
"We will not hesitate to use a big stick ... to make sure the big companies do the right thing by you, their customers," he said.
The prime minister has also stressed that his predecessor Tony Abbott once spruiked the emissions reduction target in his energy plan, the 26 per cent cut by 2030 pledged under the Paris climate agreement.
"As Tony Abbott said in 2015, it is a strong and responsible target, environmentally and economically responsible."
Mr Turnbull said under a new law, any government that wanted to change the target in the future will have to inform Australians of what impact that may have on their power bill.
The announcement comes as the prime minister moves to shore up his own job, with some MPs concerned enough to encourage Home Affairs Minister Peter Dutton stand against him.
Mr Dutton on Saturday tweeted that Mr Turnbull has his support.
Deputy Nationals Leader Bridget McKenzie said she learnt of the changes to Mr Turnbull's policy through his public announcement and expected to be briefed on them at a cabinet dinner on Sunday night.
Asked whether she backed Mr Turnbull, the senator said his government's record speaks for itself.
"I think Malcolm Turnbull is our prime minister and I would like to see him stay as prime minister," she told Sky News on Sunday.
