WASHINGTON (Reuters) - President Donald Trump on Monday called for a “full and complete” sentence for his former lawyer Michael Cohen, accusing him of lying about Trump’s business dealings with Russia during the 2016 presidential campaign to get reduced jail time.

FILE PHOTO: U.S. President Donald Trump's former lawyer Michael Cohen exits Federal Court after entering a guilty plea in Manhattan, New York City, U.S., November 29, 2018. REUTERS/Andrew Kelly/File Photo

Cohen, who is cooperating with a federal probe into whether Trump’s campaign worked with Russia to sway the election, is scheduled to be sentenced on Dec. 12 after pleading guilty to tax evasion, making false statements to a bank, campaign finance violations, and lying to Congress.

In a court filing last week, Cohen said he had pursued a proposed Trump Organization real estate project in Moscow with Russian government officials well into the presidential campaign, with Trump’s knowledge.

Cohen, once Trump’s self-described “fixer,” admitted he lied to Congress when he said efforts to pursue the Moscow project ended in January 2016, when they actually continued until June 2016, after Trump had clinched the Republican presidential nomination.

Lawyers for Cohen asked a federal judge in New York on Friday not to sentence him to prison.

After the plea deal, Trump described Cohen as weak and a liar and said he himself did nothing wrong in relation to the Moscow project.

In a series of tweets on Monday, the president accused Cohen of cooperating with Special Counsel Robert Mueller’s Russia probe in exchange for a reduced sentence on the unrelated tax fraud and campaign finance charges.

“‘Michael Cohen asks judge for no Prison Time’. You mean he can do all of the TERRIBLE, unrelated to Trump, things having to do with fraud, big loans, Taxis, etc., and not serve a long prison term?” Trump said. “He lied for this outcome and should, in my opinion, serve a full and complete sentence.”

Trump has described Mueller’s probe as a political witch hunt. Russia denies interfering in the U.S. election.

It is unusual for a U.S. president or any senior government official to comment on court proceedings. Trump has regularly opined on sensitive judicial proceedings from the special counsel’s case to federal appeals court rulings.

Several lawyers said Trump’s tweet amounted to witness tampering.

PARDON ROULETTE

Trump’s comments about Cohen contrasted with his expressions of sympathy for former associates caught in the web of Mueller’s investigation, including former 2016 campaign chairman Paul Manafort, who faces sentencing after being convicted of tax and bank fraud charges.

The Republican president has refused to rule out a pardon for Manafort.

On Monday, Trump praised longtime associate and Republican operative Roger Stone, who has been under scrutiny by investigators over his comments about leaked Democratic emails during the 2016 presidential campaign. Stone told ABC News on Sunday he would not testify against Trump and has not discussed a pardon with the president.

“Nice to know that some people still have ‘guts!’” Trump said in another Twitter post on Monday.

There was a strong case against the president for witness tampering because of his prior acts and statements, like dangling the possibility of a pardon for his Manafort, legal experts said.

George Conway, who is married to senior Trump adviser Kellyanne Conway, retweeted Trump’s tweet with a reference to a U.S. statute on witness tampering and obstruction of justice: “File under ‘18 U.S.C. §§ 1503, 1512.’”

“I think it is both obstruction and witness tampering,” said Lisa Kern Griffin, a former federal prosecutor and law professor at Duke University. “He (Trump) is attempting to influence an ongoing investigation in an overt way.”

Federal law makes it a crime to knowingly intimidate, threaten, or persuade another person to withhold testimony in an investigation.

It is highly inappropriate for a president to insert himself into a judicial process, said Jens Ohlin, a professor at Cornell Law School. “He’s not just a regular person. He’s the head of the executive branch.”