Senator John McCain, a member of the US Congress for 22 years and the co-sponsor of recent campaign finance reforms, has often rejected the unhealthily close links that can exist between corporate America and lawmakers and officials in Washington. But the Vietnam war hero's warning to his Senate colleagues last month of the cosy collusion between the US Air Force and defence companies went beyond his previous denunciations of corporate "pork".

Illustrating a 45-minute speech with some of the thousands of e-mail messages that he and his staff have requisitioned, Mr McCain accused officials of "systematic failure in procurement oversight, wilful blindness or rank corruption". It was the latest salvo in a three-year campaign against one of the biggest procurementdeals by the US Air Force: a $23.5bn order for 100 aircraft refuelling tankers from Boeing, the aerospace group.