Petrol price-fixing allegations shock MPs
Ministers are calling on energy firms to collaborate with the European Commission's probe into petrol price-fixing.
David Cameron, Nick Clegg and energy secretary Ed Davey all demanded that BP, Royal Dutch Shell and Statoil cooperate with cross-border efforts to determine the truth of the allegations.
All three firms have said they are cooperating with anti-trust regulators after raids on BP and Royal Dutch Shell's offices in London, and Statoil's office in Stavanger, Norway.
Clegg, standing in for Cameron in prime minister's questions, said the allegations were "incredibly serious".
"I think it is important on all of our behalfs… that those companies now engage seriously in looking at the allegations put to them," he said.
"The European Competition Commission is concerned the companies could have colluded in reporting distorted prices to a price reporting agency to manipulate the published price for oil and biofuel products," Davey explained to MPs.
"This could amount to violations of European antitrust rules that prohibit cartels and restrictive business practices and abuses of a dominant market position."
Shadow energy and climate change secretary Caroline Flint told MPs: "Consumers need to know the prices they pay for their energy or petrol are fair and transparent and are not being manipulated by traders."
Davey responded in a statement after PMQs: "We take these allegations extremely seriously.
"If it turns out to be the case that hard-pressed motorists and consumers have been hit in the pocket by manipulation of the markets, the full force of the law should be [brought] down upon them, there's no doubt about that."
Conservative backbencher Robert Halfon, a prominent campaigner on petrol issues, called for the law to be changed to ensure custodial sentences for those found guilty of fixing oil prices.
He also dismissed the Office of Fair Trading's recent investigation into the issue as a "lettuce-like inquiry" that should have been pursued much more robustly.
Davey had said the OFT did not receive evidence of manipulation of the prices. It did suggest such moves are possible, however.
Lib Dem MP Duncan Hames later asked: "How can fines possibly compensate consumers?"
Davey reminded MPs that "these are allegations… it is really important people remember that". He said lower prices remained a possibility.
