MOSCOW (Reuters) - Russian opposition leader Alexei Navalny has no chance of taking part in next year’s presidential election because of a previous conviction for embezzlement, the head of Russia’s election commission told TV Rain late on Wednesday.

Russian opposition leader Alexei Navalny talks to journalists during a hearing at a court in Moscow, Russia, June 12, 2017. REUTERS/Sergei Karpukhin

Navalny, an outspoken critic of President Vladimir Putin, has said he wants to run for the presidency in March 2018. Putin, who has dominated Russia’s political landscape for 17 years, is widely expected to run for what would be his fourth term, but has yet to confirm he will do so.

Navalny has become the most prominent opposition challenger after organizing some of the biggest anti-Kremlin protests in years, seeking to leverage public anger over what he says is grotesque official corruption to boost his popularity.

But he suffered a setback in February when a court handed him a suspended five-year jail term for embezzlement in a case he said was trumped up to frustrate his presidential bid.

Ella Pamfilova, the head of the Central Election Commission, told TV Rain late on Wednesday that the conviction meant a presidential run by Navalny was out of the question.

“I am afraid to be discourteous,” said Pamfilova. “But I understand - and he understands himself - that he has no chance of being registered for the election due to his previous conviction.”

Her comments, made days after Navalny organized another big anti-Kremlin protest, follow those of another senior election official who last month said Navalny would have to overturn his embezzlement conviction to be able to run.

Leonid Volkov, a Navalny ally, said he thought the authorities were bluffing.

“The more they say this, the greater my certainty that there will be no other option but for them to register him,” Volkov said on social media.

For now, opinion polls show Navalny would be defeated by Putin, 64, by a wide margin if he did run. But Navalny, a 41-year-old lawyer, has embarked upon a campaign he hopes will improve his chances by harnessing the Internet and by making frequent visits to the provinces where he is less known.

He is currently serving out a 30-day jail sentence after a judge found him guilty of repeatedly violating the law on organizing public meetings following big June 12 protests.