BP is facing a congressional probe in Washington over whether its decision to shut down production at its Prudhoe Bay field was a “market strategy” designed to manipulate the oil market.

In a scathing letter sent to Lord Browne, BP chief executive, on Friday, Joe Barton, the powerful chairman of the House energy committee, suggests the Alaska shutdown could be part of a wider strategy by BP to influence the market, particularly in light of recent allegations by US regulators that the company engaged in illegal trading in the propane gas market. The company has denied those allegations.

The lawmaker is understood to be incensed particularly by the shutdown because staff at the energy committee received reassurances from BP just a few months ago that a March oil spill, the result of a corroded pipeline, was “an anomaly”.

“Following on the heels of the BP refinery disaster that killed 15 people in Texas City in 2005, and the oil spill . . . this latest incident once again calls into question BP’s commitment to safety, reliability, and the responsible stewardship of America’s energy resources,” Mr Barton said.

Barton is a mouthpiece in Congress for the Oil Patch Boys. So, is the question raised on behalf of American consumers — or just finger-pointing at a competitor?