Last month, Fu Chengyu, CNOOC's chairman and chief executive, hailed the Chinese company's US$18.5bn bid for the US oil and gas group Unocal as "good offer for Unocal . . . a good offer for America".

On Tuesday, US lawmakers showed just how much they disagree with that statement. By passing a legislative amendment that delays the conclusion of any regulatory probe into a CNOOC/Unocal merger by nearly two months, they pushed a rival US$17.3bn cash-and-share offer from Chevron a step closer to the finishing line.