Treasurer Jim Chalmers has warned service stations not to rip off drivers by taking advantage of the widening conflict in the Middle East.

Chalmers earlier this week asked the Australian Competition and Consumer Commission to monitor prices as the Iran war unfolded, while pointing to looming hikes in fuel prices.

“We don’t want to see people taken for mugs at the bowser,” he told ABC News Breakfast on Thursday.

“Service stations should not be doing the wrong thing by their customers, using the conflict in Iran and the Middle East more broadly as an excuse to gouge customers.”

Chalmers said “there are legitimate concerns about the potential for some opportunistic pricing”.

Following the launch of US-Israel strikes on Iran last weekend and Tehran’s retaliatory strikes, suppliers in the Middle East have begun to halt production. Iran has also closed the world’s major oil corridor, the Strait of Hormuz.

Australians have rushed to service stations to fill up ahead of big jumps in petrol prices.

The NRMA has called out the “completely unjustifiable” prices set in the days following the outbreak of conflict.

“Oil companies are using the Middle East crisis as an excuse to jack up margins,” spokesman Peter Khoury said.

Analysis found about half of service stations in Melbourne and Sydney on Wednesday were charging between 219.9 and 223.9 cents a litre.

Opposition Leader Angus Taylor said the Coalition was well aware of the sharp rise in retail prices and the pressure that added on households.

“The Treasurer claims that the ACCC is the tough cop on the beat here, I think the cop needs to get a bit tougher,” he told Melbourne radio station 3AW.

-AAP