KIROV, Russia — Russian opposition leader Alexei Navalny asked an appeals court on Wednesday to throw out a theft conviction and five-year jail sentence he was handed in July, saying the charge was fabricated and politically motivated.

An anti-corruption blogger who helped lead a wave of protests that erupted two years ago, Navalny was found guilty of stealing timber while working as an adviser to the governor of the remote Kirov region in 2009.

He is seeking to overturn a conviction he has described as President Vladimir Putin's revenge for his activism.

"I think the political motivation of this case is evident to everybody," Navalny said in a cramped courtroom in Kirov, 1,000 kilometers (620 miles) northeast of Moscow. He accused the trial judge of rubber-stamping a "fabricated indictment."

Jailing Navalny, 37, would keep Putin's most prominent critic out of elections for years, curtailing any threat from a rival with presidential ambitions who scored a strong second-place showing in a Moscow mayoral vote last month.

But it could also revive street protests by Putin's opponents and human rights activists over what they see as a clampdown on dissent since the 61-year-old president started a six-year third term in 2012.

It would add to Western concerns about the rule of law in Russia and Putin's treatment of opponents at a time when he is gearing up to showcase the country he has led for nearly 14 years at the Sochi 2014 Winter Olympics in February.

A blogger against corruption among Russia's elite, Navalny helped lead the biggest protests of Putin's rule, which were stoked by allegations of fraud in favor of the ruling United Russia party in the December 2011 parliamentary election.

The protests have faded, but Navalny has emerged as the main opposition leader. A day after his conviction, Navalny was unexpectedly freed from custody pending appeal, allowing him to continue his campaign for Moscow mayor.

Some analysts say the Kremlin was betting he would suffer a humiliating defeat, but he won 27 percent and nearly forced the incumbent, Putin's ally Sergei Sobyanin, into a runoff