Russian opposition leader Alexei Navalny appeared in a Moscow court on Friday for the second time this week, this time on a charge of defaming a World War II veteran

The politician, who was ordered earlier this week to serve two years and eight months in prison, slammed the new hearing as a “disgusting PR trial” intended by the Kremlin to disparage him.

Last June, Russia’s Investigative Committee launched a probe into Navalny on charges of defamation, after the politician slammed people featured in a video promoting the constitutional reform that allowed an extension to President Vladimir Putin’s rule as “corrupt stooges,” “people without conscience” and “traitors.”

The authorities maintained that Navalny’s comments “denigrate (the) honor and dignity” of a World War II veteran featured in the video. If convicted, Navalny faces a fine or community service.

“This trial was conceived as some kind of PR trial, because the Kremlin needs headlines, ‘Navalny slandered a veteran’,” the politician said in the courtroom Friday.

Last month the 44-year-old Navalny, an anti-corruption investigator and Putin's most prominent critic, was arrested upon returning from Germany, where he spent five months recovering from a nerve-agent poisoning that he blames on the Kremlin. Russian authorities rejected the accusations.

A Moscow court on Tuesday found that Navalny violated probation terms of his suspended sentence from a 2014 money-laundering conviction, and ordered him to serve two years and eight months in prison.

The politician's arrest and jailing triggered massive protests across Russia, in which tens of thousands took to the streets to demand his release. Many protesters also chanted slogans against Putin in the largest show of discontent in years. Thousands of protesters have been detained.