Democrats on the House Judiciary Committee plan to hold a mock hearing on Tuesday — behind closed doors — to prep for Robert Mueller’s upcoming congressional testimony, a report says.

Multiple sources, speaking on the condition of anonymity, told the Associated Press about the practice run on Monday night, but didn’t offer any details about what will take place.

The House Judiciary and Intelligence committees are going to be grilling former special counsel Mueller about his Russia probe, which sought to uncover evidence of election meddling during the 2016 presidential race.

Mueller’s investigation report listed no proof of a criminal conspiracy between the Trump campaign and Moscow, but said it could not clear the president of trying to obstruct justice.

The ex-FBI director has told reporters that he doesn’t plan to testify about anything other than what was listed in his report when he appears Wednesday before congress.

The chairman of the House Judiciary Committee, Rep. Jerry Nadler, ​said Sunday that ​he believed the hearing could kick off impeachment proceedings against President Trump.

“The (Mueller) report presents very substantial evidence that the president is guilty of high crimes and misdemeanors,” Nadler told “Fox News Sunday.”

“We have to let Mueller present those facts to the American people and then see where we go from there,” Nadler added. “Because the ​​administration must be held accountable and no president can be above the law.”

Republicans are expected to use their time Wednesday questioning Mueller about alleged corruption at the FBI, which kicked off the Trump campaign probe – and was dismissed by Nadler as “irrelevant.”

“Let them waste their time,” Nadler said of the GOP.

With Post Wires