The end of a 22 cent cut to petrol taxes next week shouldn't trigger an immediate spike in prices at the bowser, federal Treasurer Jim Chalmers says.
The federal government has refused to extend a temporary halving of the fuel excise that was introduced by the former government earlier this year after Russia's invasion of Ukraine caused massive global spikes in the price of oil.
The discount is due to end from Thursday, September 29.
But Mr Chalmers said he did not expect a jump in petrol prices next week, with millions of litres bought at cheaper prices still being held in storage
"Fuel prices in most parts of the country at the moment are now around 50 cents a litre below the peak recorded in July," Mr Chalmers said.
"Industry estimates that there [will] be more than 700 million litres of lower excise fuel in the system when the fuel excise is reintroduced.
"This is 700 million reasons why the price should not shoot up by the full 23 cents on the night that the excise relief ends."
Mr Chalmers said fuel prices were also 50 cents per litre cheaper than the peak in July.
The fuel watchdog recently reported that there was an average six-week lag among fuel retailers between when the excise relief was introduced and when that flowed on to cheaper fuel at the bowser, as retailers worked through existing stock bought at higher prices.
The ACCC said it expected a similar lag when the higher excise returns, and would be watching closely for retailers who may seek to take advantage of it.
"We expect that there will be no uncharacteristic or abnormal retail price increases in the days leading up to, on the day of, or after the reintroduction of the full rate of fuel excise," it said last week.
"Following the excise reintroduction, the ACCC will be monitoring wholesale and retail prices closely and will not hesitate to take action where there is evidence of misleading or deceptive conduct, misrepresentation about the excise increase and retail prices, and anti-competitive behaviour."
