Dick Cheney, US vice-president, will be called to testify as a witness at the trial of Lewis “Scooter” Libby, his former chief of staff who stands accused of lying to a grand jury investigating the leaking of a CIA agent’s name, a defence lawyer said on Tuesday.

Mr Cheney could become the first sitting vice-president to testify in a criminal case if he appears on behalf of Mr Libby, who has been charged with five counts of obstruction of justice, perjury and making false statements. Only last week, Patrick Fitzgerald, the special prosecutor leading the investigation into the leaking of Valerie Plame’s name, said he would not call Mr Cheney to testify. But Ted Wells, a defence attorney for Mr Libby, said in court yesterday: “We’re calling the vice-president.”