'Be wary of making rash decisions about the constitution'

A professor of federal jurisprudence at Columbia Law School has said Congress should not be putting Donald Trump on trial because the US constitution does not allow proceedings now that he has left the role of president.

Prof Philip Bobbitt told BBC World News: “The problem here is the president is no longer in office, he’s no longer a civil officer, even though he was when he was impeached - and you can’t convict a private party.”

He also warned that decisions about the constitution that are made in the heat of the moment "have a way of opening the door to other decisions that I think we would want to be more circumspect about".

The US Senate rejected similar claims from the former president’s defence team, that he should not face an impeachment trial now that he has left the White House, enabling proceedings to begin.