After weeks of guarded, diplomatic language through gritted teeth, BP has been provoked to the point where it can no longer be polite.

Peter Sutherland, the company’s outspoken chairman, on Thursday attacked BP’s Russian partners in the TNK-BP joint venture and criticised Russia’s leaders. “The fate of TNK-BP will be an early test of the ability of President [Dmitry] Med­vedev to turn his vision [of restoring respect for the rule of law] into reality,” Mr Sutherland said. “Much of the world is watching as well.”