(CN) – Attorney Alan Dershowitz, a frequent defender of President Donald Trump, said Sunday that Special Counsel Robert Mueller’s final report on his probe of Russian meddling in the 2016 election is likely to be “devastating” to the president.

“I think the report is going to be devastating to the President,” Dershowitz, a fomer Harvard law professor, said on “ABC This Week.”

“And I know that the President’s team is already working on a response to the report,” he said.

But Dershowitz went on to say that he doesn’t think any criminal charges will be brought forward against the president.

“When I say devastating, I mean it’s going to paint a picture that’s going to be politically very devastating,” he said. “I still don’t think it’s going to make a criminal case, because collusion is not criminal.”

When the report will be made public is still anybody’s guess. Dershowitz noted that its release will be the call of new acting Attorney General Matthew Whitaker, who replaced the fired Jeff Sessions after the November midterm election.

In the meantime, Trump, who has repeatedly derided Mueller’s investigation as a “witch hunt” and insisted there was “no collusion” between his campaign and Russia, kept up his critiques Monday morning.

“When Mueller does his final report, will he be covering all of his conflicts of interest in a preamble, will he be recommending action on all of the crimes of many kinds from those “on the other side”(whatever happened to Podesta?), and will he be putting in statements from …” Trump tweeted.

The president has accused Mueller of being a partisan out to get him despite the fact the former FBI chief is a Republican and was appointed to the lead the agency by former Republican President George W. Bush.

Trump continued on Twitter: ” … hundreds of people closely involved with my campaign who never met, saw or spoke to a Russian during this period? So many campaign workers, people inside from the beginning, ask me why they have not been called (they want to be). There was NO Collusion & Mueller knows it!”

Mueller was appointed special counsel in May 2017, after Trump fired then-FBI Director James Comey.