The Government is demanding a drop in the price of petrol after a pre-Christmas cut failed to eventuate.
Energy Minister Gerry Brownlee says international crude oil prices have been sitting at a low of between $US35 and $US37 per barrel in recent weeks.
The New Zealand dollar at the same time has climbed in value against the US dollar.
Mr Brownlee says he acknowledges that price cuts were made in November.
But he would be disappointed if the oil companies are waiting until after the holiday season, and high volume sales period, before deciding to act.
Both Shell and Chevron, which markets Caltex, say the time of year does not affect how prices are calculated.