WASHINGTON (REUTERS) - After US President Donald Trump fired FBI Director James Comey on Tuesday (May 9), Democratic members of Congress denounced the move and renewed calls for an independent investigation of alleged Russian meddling in the 2016 US presidential campaign.

Democrats likened the dismissal to President Richard Nixon's firing of an independent special prosecutor during the Watergate investigation and discounted Mr Trump's contention that the move was related to the Federal Bureau of Investigation probe of the e-mails of Mrs Hillary Clinton, Mr Trump's rival for the presidency.

Here are reactions from Democrats and Republicans to Mr Comey's firing:

Democratic Senator Patrick Leahy

"No one should accept President Trump's absurd justification that he is now concerned that FBI Director Comey treated Secretary Clinton unfairly... This is nothing less than Nixonian."

Democratic Representative John Conyers

"Today's action by President Trump completely obliterates any semblance of an independent investigation into Russian efforts to influence our election and places our nation on the verge of a constitutional crisis."

Republican Senator Lindsey Graham

"Given the recent controversies surrounding the director, I believe a fresh start will serve the FBI and the nation well."

Democratic Senator Bob Casey

"This is Nixonian. Deputy Attorney General Rod Rosenstein must immediately appoint a special counsel to continue the Trump/Russia investigation."

Democratic Senator Chuck Schumer

"Earlier this afternoon, President Trump called me and informed me he was firing Director Comey. I told the president, 'Mr President, with all due respect, you are making a big mistake'... Given the way the president has fired Director Comey, any person who he appoints to lead the Russia investigation will be concerned that he or she will meet the same fate as Director Comey if they run afoul of the administration."

Democratic Representative Elijah Cummings

"There is now a crisis of confidence at the Justice Department and President Trump is not being held accountable because House Republicans refuse to work with us to do our job."

Democratic Senator Mark Warner

"The president's actions today are shocking. ... The only way this administration can begin to demonstrate a commitment to the rule of law ... is to cooperate fully with the ongoing congressional investigations and to support the appointment of an independent special counsel."

Fugitive former National Security Agency contractor Edward Snowden

"This FBI director has sought for years to jail me on account of my political activities. If I can oppose his firing, so can you."

Republican Senator Charles Grassley

"Over the course of the last several months, Director Comey's decisions on controversial matters have prompted concern from across the political spectrum and from career law enforcement experts."

Democratic Senator Ron Wyden

"There can be no question that a fully independent special counsel must be appointed to lead this (Russia) investigation. At this point, no one in Trump's chain of command can be trusted to carry out an impartial investigation."

Republican Senator Bob Corker

"It is essential that ongoing investigations are fulsome and free of political interference until their completion, and it is imperative that President Trump nominate a well-respected and qualified individual to lead the bureau at this critical time."

Republican Senator John McCain

"James Comey is a man of honour and integrity and he has led the FBI well in extraordinary circumstances. I have long called for a special congressional committee to investigate Russia's interference in the 2016 election. The president's decision to remove the FBI director only confirms the need and the urgency of such a committee."

Democratic Senator Richard Blumenthal

"The need for a special prosecutor is now crystal clear. President Trump has catastrophically compromised the FBI's ongoing investigation of his own White House's ties to Russia. Not since Watergate have our legal systems been so threatened."

Conservative watchdog group Judicial Watch

"This is an important move to restore public confidence in the fair administration of justice at the federal level. Mr. Comey did not seem to understand some of the laws he was asked to investigate and unfortunately politicised his sensitive position as the FBI director."