ALL companies must make a profit to be viable - that goes without saying.

But that does not mean anything goes. When the industry in question produces a lifeline commodity like vehicle fuel, it must be able to justify keeping consumer prices high when its costs fall.

Oil companies and other petrol and diesel retailers are rightly being asked tough questions about their failure to make quicker price cuts on the forecourt after a big drop in the price of crude oil. There was little sign of hesitation by them in putting the prices up when oil costs were rising.

Though some supermarkets did drop prices a little earlier this month in response to calls from the Chancellor, motoring organisation the AA has completed a telling analysis showing that although the wholesale price of petrol is back to where it was four years ago, the pump price of petrol is still a lot higher. It notes that since November 2010 the rise in petrol's wholesale price across north west Europe has been much lower than the rise in the margins for retailers, suppliers, refiners and petrol commodity traders. It is not just the forecourts, then.

This is highly reminiscent of the controversy surrounding the Big Six energy companies which have been rightly criticised for raking in big profits while introducing huge hikes in consumer charges. Have the price increases simply been funding the companies' big profits? The controversy over that not only dominated the political agenda for weeks last autumn, but highlighted the opaque nature of energy costs and pricing.

While members of the public suspected the firms of something approaching legal profiteering, the companies insisted they were pricing fairly, given the huge infrastructure development commitments they faced.

The AA wants more transparency about oil, wholesale and pump prices too. The organisation claims foot-dragging by retailers in lowering prices is not the whole story, pointing to higher VAT, wobbly exchange rates and those higher margins for companies involved in producing and supplying fuel. The AA is right to call for the European Commission investigation into oil and fuel prices to give a progress report on exactly why it is that this disparity exists between wholesale prices and the cost to consumers, especially after an earlier Office of Fair Trading investigation into petrol prices was criticised for concluding the UK petrol market was working well.

There are some transactions in which the onus is on the consumer to judge whether an item has been fairly priced and to walk away if they feel it has not. But petrol and diesel are not expensive trinkets in an antique shop: they are critical to people's lives. Their cost affects the price of food and other essentials. The Scottish island fuel rebate helps keep down fuel prices in areas where the price of fuel is particularly high due to transport costs, but Government action is not the immediate issue here.

What is required is fair play by all companies involved in the production and supply of petrol and diesel.