The FuelWatch scheme will force metropolitan and regional petrol stations to publicise their prices for the following 24 hour period at 2pm each day in a bid to give motorists more choice.

A 2007 report from the competition watchdog predicted the program could shave two cents a litre of the price of petrol.

FuelWatch is already operating in Western Australia and will start nationally by December 15.

What we want to do is ensure motorists are not paying one cent more than they have to at the bowser," Mr Rudd told reporters.

"What we want to do is ensure that motorists are able to buy the cheapest petrol at the cheapest prices at the cheapest petrol stations and at the cheapest times."

FuelWatch will be headed by the Australian Competition and Consumer Commission (ACCC) petrol commissioner Pat Walker, who previously ran the WA program.

The plan was met with criticism from the opposition and motoring groups over concerns FuelWatch would mean an end to the weekly discount cycle.

"I think we've got to be concerned that Mr Rudd's creating this petrol price commissioner which is really just another pair of hands at the ACCC," Opposition Leader Brendan Nelson told reporters in Brisbane.

"The battlers who are filling up early in the week are likely to lose the discounting that they get early in the week."

Opposition competition policy spokesman Peter Dutton said Mr Rudd had to nominate a price drop that would mark FuelWatch a success.

"We are calling on Kevin Rudd to guarantee no motorist will be worse off under this scheme," Mr Dutton said.

South Australian motoring group the Royal Automobile Association warned FuelWatch would not benefit their members.

"Seventy one per cent of SA motorists are aware that Tuesday is the cheapest day of the week to buy fuel and 76 per cent buy fuel weekly," association senior analyst Matthew Hanton said earlier this week.

"If FuelWatch was introduced, then those motorists that shop smart and wait for the cheapest days, as well those that are struggling due to rising fuel costs, will essentially be disadvantaged and forced to pay an even higher price for fuel."

With FuelWatch eight months away there will be no immediate relief for motorists who are now paying record prices for petrol.

World oil prices has nudged fresh highs, heading above $US112, amid supply concerns and further weakening of the US dollar.

Adding to price pressure was a temporary shutdown of a pipeline that moves oil in the midwest of the US.

Mr Rudd admitted the government could only do so much to alleviate the financial pressure of petrol prices.

"Petrol prices will always be linked to fluctuations in international oil markets," he said.

"If the global price of crude oil goes up, Australian retail prices will be affected.

"The national FuelWatch scheme is not a silver bullet that breaks this nexus, no government policy can guarantee that petrol prices will always go down.

"But FuelWatch will ensure that drivers don't pay one cent more than they have to when filling up at the bowser."

-aap-ninemsn.com.au