The downward trend of petrol prices appears to have ended, for now, a leading economist says.
After weeks of slowly falling pump prices, CommSec chief equities economist Craig James believes prices are consolidating about the $1.50 a litre mark.
"In most capital cities petrol prices crept higher in the latest week after falling sharply over the past month," Mr James said.
"Based on trends in the wholesale market, the average pump price looks set to consolidate near $1.50 a litre."
The national average price of unleaded is $1.49 a litre, figures from the Australian Institute of Petroleum show.
"The average motorist is now forking out around $209 a month on petrol, a saving of around $20 from the highs in mid July, but still up $40 a month on a year ago," Mr James said.
News of the plateauing price came as key independent senator Nick Xenophon remained steadfastly opposed to the government's FuelWatch scheme, which it says will give motorists more information and choice when buying fuel.
Legislation setting up FuelWatch - scheduled to begin by December 15 - has been delayed in the Senate.
The government needs the support of Senator Xenophon and the six other cross-bench senators to get FuelWatch up and running.
"FuelWatch won't work, won't give the benefits to consumers that it's meant to," Senator Xenophon told ABC Radio today.
"If the wholesale price is determined by the big oil companies and they also control many of the outlets, it's not a level playing field for those small operators, those independent operators in the retail sector."
Prime Minister Kevin Rudd is understood to be organising a meeting with Senator Xenophon in coming days to thrash out the issue and try to win over the new senator.
The South Australian senator's concerns were echoed by his state's peak motoring body, the Royal Automobile Association.
"Central to our concerns is the fact that the proposal forces retail prices to be locked in for a 24-hour period," association spokesman Matthew Hanton said.
"By banning the intra-day price movements of fuel retailers, motorists will ultimately pay more at the pump, particularly those thousands of motorists that already shop smart and take advantage of the weekly discount cycle."