WASHINGTON, June 10 — Almost a half-century after his stunning testimony helped sink president Richard Nixon, Watergate figure John Dean is to speak in Congress today on Donald Trump’s alleged obstruction crimes.

Democrats of the House Judiciary Committee have invited the former White House counsel and two other legal experts to talk about the Mueller Russia meddling report’s allegations that Trump obstructed justice—keeping alive the possibility that they could move to impeach the president.

Dean has no role in the Russia investigation, but Trump, unable to shake accusations that he obstructed justice, has lashed out, calling him a "sleazebag attorney” in a Democratic effort to "redo” the Mueller investigation.

"For two years all the Democrats talked about was the Mueller Report,” Trump tweeted yesterday. 

"But despite the bias, when the Report came out, the findings were No Collusion and facts that led to No Obstruction.”

"But they want a Redo, or Do Over. They are even bringing in @CNN sleazebag attorney John Dean. Sorry, no Do Overs - Go back to work!”

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 spent four months in prison for his own obstruction offenses and was permanentlyy disbarred as a lawyer.

Dean likely has no inside knowledge of the Trump case, but his appearance will highlight a key parallel—that Trump’s White House counsel Don McGahn was the key source for Special Counsel Robert Mueller’s detailed description of at least ten instances in which Trump appeared to try to obstruct the investigation.

Mueller did not formally charge Trump when he concluded his investigation in March, citing Justice Department restrictions, and left it to Congress to determine whether the president had committed an impeachable crime.

"I’m clearly not a fact witness,” Dean said early Monday on CNN, where he is a regular commentator.

"But I hope I can give them some context and show them how strikingly like Watergate what we’re seeing now, and as reported in the Mueller report, is.”

"The fact that Nixon was hands-on very early is just like Trump,” he said.

"Nixon waded in and tried to influence the FBI investigation as did Trump,” he said, pointing to Trump’s firing of FBI director James Comey in May 2017. — AFP