Other oil exporting countries could chose to boost their production and make up the shortfall from Iraq. Some sources say that Saudi Arabia is willing to make up any lack of supply from Iraq. But other sources say that Opec is more likely to maintain current levels of oil production in order to ensure that wholesale prices do not fall. Any effect from Iraq's decision to halt exports would be cancelled if Opec does agree to raise production. There is also some speculation that Iraq will not really carry out its threat.
Crude oil is only one factor influencing the retail price of petrol.
Last year, Esso claimed that a retailer makes only about five pence for each litre of unleaded sold for 84p, with 61p going straight to the government in taxes. The retailer's 5p has to cover other expenses including transportation, storage and processing as well as credit card charges, which alone work out at more than 1p a litre, according to Esso. Shell claims not to have made a profit selling petrol in the UK for three years. And independent petrol retailer Save this year went into administration because of the difficulty of making a profit at the pump. Much of the anger of motorists is sparked by the huge profits made by the oil companies.