Lewis “Scooter” Libby, the former chief of staff to Dick Cheney, the US vice-president, was convicted on Tuesday on four of five counts of perjury and obstruction of justice.

Mr Libby, 56, looking ashen but resolute, showed no emotion as the jurors each solemnly spoke the single word “guilty” over and over again on the four separate counts. They related to lies Mr Libby told a grand jury about his role in revealing the identity of a CIA agent. The jury, who had deliberated for 10 days, acquitted him on one charge of making false statements to the FBI.