ACT Chief Minister Andrew Barr has helped push down petrol prices in the Territory.

Mr Barr was last week frustrated by how slow fuel prices were falling in the ACT compared to elsewhere in the country, accusing ACT retailers of price gouging.

He threatened to cap the retail margins - the difference between the wholesale and bowser price - of service stations if prices were still above $1 per litre after the weekend.

He also threatened fines of up to $40,000 and six months of jail time if retailers were found gouging customers.

The following Monday, unleaded petrol at most major Canberra service stations was selling for between 101.9 and 103.9 centre per litre.

NRMA's Peter Khoury said prices would not have fallen without the ACT Government stepping in.

“It worked; prices did fall significantly,” he said.

“We're finally seeing prices falling in Canberra and it took the threat of government regulation to do it.”

The average price of unleaded fuel has dropped from 113 to 102.8 cents per litre in the last week.

Mr Khoury says prices to fall further.

“We know now that prices can fall, and there's no reason why the ACT can't get to below $1 [for unleaded],” he said.

“We should see it fall another couple of cents and it should stay at this level now for quite some time. This should be the new norm.”

Mr Barr said retailers appear to have heeded the warning to significantly drop prices.

“I'm targeting the Australian average petrol price as being what would be appropriate for our market,” Mr Barr said.

“Canberra at the moment would appear to be at, or thereabouts, the Australian average and that's where we should aim to be for the longer term.”

Still, the Chief Minister says he is planning to set a new target for retailers based on national market petrol pricing data.