A Senate Intelligence Hearing today heard that the investigation into the alleged links between the Trump Campaign and Russia will continue unhindered.

"There has been no effort to impede our investigation to date," acting FBI director Andrew McCabe told the Senate Intelligence Committee, in a hearing that capped two days of high drama provoked by the dismissal.

"You cannot stop the men and women of the FBI from doing the right thing," he said.

"All of the agents involved in the investigation are still in their positions."

The hearing came as Rod Rosenstein, the US deputy attorney general reportedly threatened to quit after it emerged that the Trump administration intended to use his letter regarding James Comey's conduct during the election to justify firing the FBI director.

The revelations came as senators said they would question Mr Rosenstein. Chuck Schumer, the Senate minority leader said his involvement in the firing of Mr Comey had brought his "integrity" into question.