Donald Trump must be investigated by Congress for abuse of power, says George W Bush's ethics lawyer

It comes just weeks after Richard Painter called for US President to be impeached if he refused to fully comply with Russian enquiry

President Trump's behaviour has shocked the political establishment (AP)

Donald Trump should face a Congressional investigation into the possible abuse of power of his office, according to George W Bush’s former ethics lawyer.

Richard Painter has called for an urgent meeting of the House Judiciary after the US President dismissed FBI Director James Comey, who was leading an investigation into allegations of Russian collusion in Mr Trump’s election campaign.

Richard Painter served as President George W Bush's ethics lawyer between 2005 and 2007 (University of Minnesota Law School)

It comes just weeks after Mr Painter called for Mr Trump to be impeached if he refused to fully comply with the Russian probe by releasing documents relating to former national security adviser Michael Flynn.

“Nixon had to go through three AGs to fire the man investigating Watergate. POTUS should not be allowed to fire the man investigating him,” he wrote on Twitter.

“House Judiciary should convene tomorrow morning to hold a hearing on abuse of power by the President.”

Mr Painter, who served as the White House chief ethics lawyer between 2005 and 2007, called the scandal “a lot worse than Watergate”.

"We cannot tolerate this – for the president to be firing people who are investigating him and his campaign and its collusion with the Russians, it's a lot worse than Watergate,” he told Rolling Stone.

“Watergate was a third-rate burglary. It was purely domestic in nature. This situation involves Russian espionage, and we've got to find out who is collaborating."

Mr Trump ordered his private security guard to hand-deliver Mr Comey’s termination letter on Tuesday, claiming errors made in the FBI investigation into Hillary Clinton’s use of a private email server during the election campaign left Mr Trump no choice but to dismiss him.

The decision sent shockwaves through Washington, as many accused him of trying to gag the Russian investigation, citing the many instances on the campaign trail where Mr Trump offered his support to the investigation into Ms Clinton.