MOSCOW (AP) — Russian opposition leader Alexei Navalny says that he's been barred from leaving Russia.

Navalny said in a blog post on Tuesday that he was due to travel to France to attend a hearing in the European Court for Human Rights when he was stopped by border guards and told that a ruling by court bailiffs have barred him from leaving Russia.

Navalny, who is widely considered to be the most prominent political opponent of President Vladimir Putin, 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 barred from traveling in the past but the ban was lifted in spring last year when he had to leave to Spain for urgent medical treatment.