Attempts by the US Congress to close a regulatory “gap” in the way the UK’s main energy futures market is overseen – dubbed “the London loophole” – is unlikely to have any effect on record crude oil prices, the US owners of London’s oil futures exchange said on Thursday.

Debate has been raging in Washington over whether speculation in the oil and oil futures markets could be a factor behind record oil prices. Next week, the Treasury select committee holds the first hearing in Britain into the issue.