Gull has slashed 10c a litre off the price of petrol for the remainder of Easter, putting pressure on the bigger fuel companies.
The drastic cut comes as the Automobile Association issues a call for prices at the pump to drop further.
AA PetrolWatch spokesman Mark Stockdale said that despite recent drops in petrol prices, the fuel companies could still afford to give motorists a better deal.
"Our monitoring shows the commodity price for petrol and diesel has fallen 6c a litre in the past month. But retailers have only dropped by 4c for petrol and 3c for diesel. We're disappointed that they haven't been quick to pass on the savings."
Gull says it will discount fuel by 10c a litre from 10am today until 10am on Tuesday. At unmanned Gull sites, 91 petrol will sell for $1.999. Supermarket vouchers can be used at manned sites only, on top of the discount.
Stockdale welcomed the offer but said discounts should have happened on Friday, when people were fuelling up for the weekend.
Gull general manager Dave Bodger said the company could afford to be cheaper because it had lower operating costs.
Bodger estimated Gull sold about 4 per cent of the country's petrol.