Motorists are being warned to brace for pain at the petrol pump after the consumer watchdog flagged fuel prices are again on the rise.

The Australian Competition and Consumer Commission on Thursday revealed that petrol prices dropped to an average 109.2 cents-per-litre (cpl) in January, their lowest level in six years.

But the watchdog said retail prices across Australia’s five biggest cities had started to pick back up this month due to lifting international oil prices.

Prices in country regions remained higher than in the cities, the ACCC report also found.

NRMA spokesman Peter Khoury warned motorists of higher prices in the coming weeks as they started to trend upwards.

“We need to start bracing ourselves for the fact that some of the lower prices, particularly in the capital cities, are going to go up,” Mr Khoury told AAP.

The good news, he said, was that prices probably wouldn’t hit highs of about 150cpl experienced in capital cities early in 2014.

“They certainly shouldn’t go up to the levels we saw last year,” Mr Khoury said.

In its report, issued quarterly, the ACCC said of the five biggest cities Perth recorded the highest monthly average petrol price in January, of 115.0cpl.

That was followed by Brisbane (112.4cpl), Melbourne (108.1cpl), Adelaide (105.8cpl) and Sydney (104.6cpl).

Overall, Darwin was the most expensive capital city in which to buy petrol, with drivers paying an average 135.4cpl.

Mr Khoury said continued action from the watchdog was needed to reduce the gap between city and country fuel prices.

“Putting more scrutiny on the regional prices will be really beneficial because it means the ACCC will be in a better position to be able to respond and react when there is that gap,” Mr Khoury said.

The ACCC says it will be watching the issue closely over the next three months.

On Thursday, the cheapest petrol in Sydney was 112.0cpl at a service station at Pennant Hills, according to monitoring website

In Melbourne, petrol was cheapest at 107.5cpl at an outlet at Trafalgar.

Extracted in full from Nine News.