The US House of Representatives was poised on Wednesday officially to charge Donald Trump with inciting an insurrection against the US government in the wake of the attack on the US Capitol on 6 January by a pro-Trump mob, an extraordinary and historic measure that would make him the only American president ever to be impeached twice.

The unprecedented effort gained momentum overnight as senior Republican leaders in the House joined Democrats in calling for his removal from office for his role in inflaming a horde of loyalists who led the deadly assault on the US Capitol while members of Congress in both the House and Senate were in session to certify Joe Biden’s victory over Trump in November’s presidential election.

A remorseless Trump called his inflammatory language at a rally immediately prior to the mob marching on the US Congress and breaking in last week “totally appropriate”.

He said impeachment was nothing more than a “continuation of the greatest witch hunt in the history of politics”.