White House lawyers have reportedly started researching impeachment procedures should an attempt be made to oust Donald Trump from the office of the presidency, according to CNN.

Two people briefed on the discussions reportedly told the broadcaster lawyers in the White House counsel’s office have in the past week spoken to impeachment experts to discuss the nature of proceedings, were they to go ahead. A White House official denied the report.

President Donald Trump is facing scrutiny following reports that he attempted to pressure former head of the FBI James Comey to drop the investigation into his former national security advisor Michael Flynn.

In a memo written by Mr Comey after a meeting with the president, he recorded that Mr Trump allegedly told him, “I hope you can let this go,” according to the New York Times.

Many politicians in the US have been cautious around talk of removing the president from office, though Republican congressman Justin Amash told The Hill that if reports about the pressure proved to be true then it could merit impeachment.

Republican representative Carlos Curbelo compared Mr Trump’s alleged pressure on Mr Comey to the cases of obstruction of justice made against Richard Nixon and Bill Clinton.

“Obstruction of justice in the case of Nixon, in the case of Clinton in the late 1990s, has been considered an impeachable offence,” he told the broadcaster.

A Democratic congressmen from Texas, Al Green, became the first to call for the President to be impeached from the floor of the House, however.

"This is where I stand. I will not be moved. The President must be impeached," he said last week.

The African American congressman has reportedly received menacing phone calls since his statement, including threats of being “lynched”.