Number 10 admitted that any change in the law to prosecute anyone for allegedly fixing the pump price would be forward-looking, and would not be able to hold to account any executives caught up in the current scandal.
David Cameron said he will urgently look at “extending criminal offences” to cover market manipulation in the energy sector, after BP and Shell were raided by European authorities on suspicion of rigging oil prices.
The Prime Minister said on Wednesday that any executives should face criminal prosecution if they are found to have fixed the price of petrol.
Amid fears that British motorists could have been duped into paying thousands of pounds too much for petrol over the past decade, Mr Cameron told the companies they will face the “full force of the law” if the accusations are true.
Ministers are under pressure to take action as the investigation already has echoes of last year’s Libor controversy, which saw banks falsely report key interest rates.
Following that scandal the Government created new laws which made it an offence to manipulate the benchmark mortgage interest rate.
But Number 10 admitted any prosecutions over any petrol price-fixing could only happen if the current rules were extended to include the energy sector, possibly through secondary legislation.
If this happened, any charges could not be applied retrospectively.
The Prime Minister’s spokesman said: “Following the Libor scandal, the Government legislated to create a new criminal offence and a manipulation of all types of benchmarks.
“This law was done in such a way that other benchmarks could be included, and that would be a change in secondary legislation. Other offences including energy market manipulation could be added in if necessary.”
But he added that these changes would not apply retrospectively. The spokesman said: “The law is the law so it will apply at the point it comes in … A change in the law that makes something illegal takes effect from the moment it takes effect.”
Number 10 added that there was also an investigation ongoing by the European Commission and it “can impose a fine of 10 per cent of the overall turnover of the company”.