MOSCOW -- Russian opposition leader Alexei Navalny was stopped at the border Tuesday and barred from leaving Russia as he was about to travel to a court hearing at the European Court for Human Rights in France.

Navalny said in a blog post on Tuesday that he was due to attend a hearing at the ECHR which is expected to rule if his countless detentions have been politically motivated. He was stopped by border guards and told that a ruling by court bailiffs has barred him from leaving Russia.

The hearing in Strasbourg on Thursday could prove a major embarrassment for the Kremlin which routinely dismisses Navalny, arguably Russia's most popular opposition figure, as a trouble-maker with no political backing.

"Apparently, Putin's regime thinks (that) not letting me fly to Strasbourg to hear this ruling will change anything," he wrote on Twitter.

Navalny said later on Tuesday that the formal reason for barring him from leaving Russia was a bailiffs ruling, dated Friday, to collect from him 2.1 million rubles ($31,000) in damages in a civil lawsuit against a timber company. He lost the lawsuit last year but Navalny said the court never provided any documents or banking details for him to pay the damages.

Navalny has faced numerous criminal charges in the past that are widely viewed as attempts by the Kremlin to sideline him.

Two separate criminal cases have prevented Navalny from travelling in the past but the ban was lifted in spring last year when he had to leave to Spain for urgent medical treatment.

Navalny, who rose to prominence thanks to his investigations into official corruption, spearheaded major anti-government protests which have attracted Russians from across the political spectrum.