Anti-corruption blogger Alexei Navalny and his wife Yulia smile as they speak to the media before leaving from a railway station in Moscow July 17, 2013. Russian protest leader Navalny won a rare victory on Wednesday by being accepted as a candidate in the Moscow mayoral election which he sees as a stepping stone to challenging Vladimir Putin for the presidency. But his ability to contest September's election and the next presidential vote in 2018 depend on a judge's verdict on Thursday in the most prominent trial of an opposition figure in Russia since Soviet times. [Photo/Agencies]

Kremlin Clampdown

Navalny is the most prominent opposition leader to be tried in Russia since Soviet times.

Putin's critics accuse the president, who returned to the Kremlin in May last year for a third term, of using the law to silence his opponents after facing the biggest protests in the 13-year rule.

Putin has taken a tough stance against the opposition, which accuses him of launching a crackdown to stifle dissent following the protests, which at their peak attracted tens of thousands of people in big cities but have since dwindled.

It is also the biggest trial in Russia since the jailing of oil tycoon Mikhail Khodorkovsky in 2005 on tax evasion and fraud charges after he fell out with Putin.

Khodorkovsky's $40 billion company Yukos was then carved up and sold off, mainly into state hands. He was convicted of theft and money-laundering in a second trial in 2010.

Navalny has captured the mood of urban youth disillusioned by Putin's long rule. But he has also been dogged by accusations that he has nationalist tendencies and his appeal is limited outside the big cities.

Navalny has suggested Putin ordered the trial to silence his criticism of what he calls a political class of "swindlers and thieves" and the absence of the rule of law in Russia. The Kremlin says it does not interfere in criminal cases.