Watergate figure Dean details Trump-Nixon parallels

John Dean, the White House lawyer who helped bring about the Watergate downfall of Richard Nixon, has told Congress that there are "remarkable" similarities between the former president's illegal behaviour and alleged acts of obstruction by Donald Trump.

Dean told the House Judiciary Committee on Monday that the Mueller report, which outlines 10 possible acts of obstruction by Trump, is equivalent to the famous "road map" that prosecutor Leon Jaworski delivered to Congress in 1974, sparking impeachment proceedings against Nixon and forcing his resignation.

"In many ways the Mueller Report is to President Trump what the so-called Watergate roadmap... was to President Richard Nixon," the 80-year-old Dean told the House Judiciary Committee.

There were "remarkable parallels" between the two, especially related to obstruction of justice, said Dean, who as Nixon's White House counsel was deeply involved in illegal efforts to stifle the Watergate probe.

One of those parallels, Dean noted, was the primary role in Trump's alleged obstruction efforts of former White House counsel Don McGahn, a main source for the Mueller investigation.

McGahn, who has been prevented by the White House from testifying to Congress, "is the most prominent fact witness regarding obstruction of justice cited in the Mueller Report," Dean said as he himself was 46 years ago.

Dean's testimony came as congressional Democrats debate impeaching Trump for his interference in the special prosecutor Robert Mueller's Russia meddling investigation. It sparked an angry attack from Trump, who has struggled in vain to put the Mueller probe behind him.

On Twitter he called Dean a "sleazebag attorney" in a Democratic effort to "redo" the probe.

"Can't believe they are bringing in John Dean, the disgraced Nixon White House Counsel who is a paid CNN contributor. No Collusion - No Obstruction! Democrats just want a do-over which they'll never get!" Trump tweeted.

Trump told journalists separately that Dean has "been a loser for many years." Asked if he thought he could be forced to step down like Nixon, Trump replied: "I don't leave." "You can't impeach somebody when there's never been a thing done wrong," he added.

Dean was the top lawyer for the Nixon's White House in 1972 when the president sought his help to cover up his staff's involvement in the break-in of Democratic offices at the Watergate complex.

Facing criminal prosecution, Dean turned against Nixon, laying out his own work with the president to hide their ties to Watergate.

He was sentenced to one to four years in prison, but was freed after four months, during which he gave evidence against other key Watergate conspirators.

In recent years he has been a commentator on politics for CNN.

Republicans on the committee accused Democrats of putting on the hearing which included three other witnesses for show, as none of those testifying had any direct knowledge of the Mueller investigation or Trump's actions.

Representative Matt Gaetz accused Dean of making a career out of his Watergate history. "Mr Dean has made a cottage industry out of accusing presidents of acting like Richard Nixon," he said.

Calling the hearing a "frivolous exercise of going after the president," he challenged Democrats: "You guys need to get your act together and figure out if you are going to open an impeachment inquiry or not.