Moscow | Imprisoned Russian opposition leader Alexei Navalny due to hear the verdict Friday in his latest trial on extremism charges.

The prosecution has demanded a 20-year prison sentence, and the politician himself said he expects a lengthy prison term.

Navalny is already serving a nine-year sentence for fraud and contempt of court in a penal colony east of Moscow.

In 2021, he was also sentenced to 2 1/2 years in prison for a parole violation. The latest trial against Navalny has been taking place behind closed doors in the colony where he is imprisoned.

If the court finds Navalny guilty, it will be his fifth criminal conviction, all of which have been widely seen as a deliberate strategy by the Kremlin to silence its most ardent opponent.

Navalny, 47, is President Vladimir Putin's fiercest foe who exposed official corruption and organised major anti-Kremlin protests.

He was arrested in January 2021 upon returning to Moscow after recuperating in Germany from nerve agent poisoning that he blamed on the Kremlin.

The new charges relate to the activities of Navalny's anti-corruption foundation and statements by his top associates.

His allies said the charges retroactively criminalise all the foundation's activities since its creation in 2011.

Navalny has rejected all the charges against him as politically motivated and has accused the Kremlin of seeking to keep him behind bars for life.

On the eve of the verdict hearing, Navalny — presumably through his team — released a statement on social media in which he said he expected his sentence to be “huge… a Stalinist term,” referring to the Soviet dictator Joseph Stalin.

In the post, Navalny called on Russians to “personally” resist and encouraged them to support political prisoners, distribute flyers or go to a rally.

He told Russians that they could choose a safe way to resist but added “there is shame in doing nothing. It's shameful to let yourself be intimidated.”