Alexei Navalny, seen as the only Russian opposition leader who stands a fighting chance of challenging Vladimir Putin, sought Sunday to get his name on the ballot for a March presidential election, with supporters gathering across Russia to endorse the move.
Thousands of people who back the charismatic 41-year-old lawyer were meeting in 20 Russian cities to formally nominate his candidacy in the presence of electoral officials to boost his chances of making the vote.
Russian electoral officials have deemed him ineligible to run due to a criminal conviction, saying "only a miracle" would help him get registered.
Putin, 65, announced this month that he will seek a fourth presidential term, which would extend his rule until 2024 and make him the longest-serving Russian leader since dictator Joseph Stalin.
But Navalny, who has tapped into the anger of a younger generation who grew up under Putin and yearn for change, said he would not give up.
He hopes that popular support for his Kremlin bid would pressure authorities into putting his name on the ballot.
"Not letting us contest the election is impossible," Navalny wrote in a blog post this week.
The Western-educated lawyer has built a robust protest movement in the face of persistent harassment and jumped through multiple hoops as he campaigned across the country in an effort to shift attitudes amid widespread political ennui.
He says he is the only Russian politician who has run a genuine Western-style political campaign, stumping for votes in far-flung regions.
In Moscow, finding a premises for the Sunday event had been so hard that Navalny's campaign pitched a huge tent in a park on the snow-covered shores of the Moscow River.
Yury Berchenko, one of some 300 supporters who gathered in the tent, called Navalny an "honest and sincere" man, saying he should be allowed to contest the vote.
"He mobilizes people," Berchenko told the French Press Agency (AFP).
"Such a man should be president or at least take part in a debate and ask difficult questions."
Pensioner Marina Kurbatskaya also showed up in the picturesque park to support Navalny as she criticized "lies and thievery" in Russia.
"If Navalny is not allowed to run I am not going to vote," she told AFP. "I don't see anyone else who I want to become president."
Earlier Sunday supporters in the Pacific port of Vladivostok, Irkutsk, Krasnoyarsk and Novosibirsk in Siberia and other cities formally endorsed Navalny's candidacy.
According to legislation, in each city he will need at least 500 people to formally nominate his candidacy.
In Moscow alone, more than 700 people supported his candidacy at the event which at times felt like a U.S. campaign conference.
Two members of the Central Election Commission attended the Moscow event, Navalny's campaign said.
Despite a litany of problems such as corruption, poor healthcare and increasing poverty, opinion polls suggest Putin enjoys approval ratings of 80 percent and is expected to sail to victory against token opponents.
Asked why Navalny had been barred from running, Putin - who has refused to mention him by name in public — said this month the opposition was hoping for a "coup" but would not succeed.
Navalny shot to prominence as an organizer of huge anti-Putin rallies that shook Russia from 2011 to 2012 following claims of vote-rigging in parliamentary polls.
The rallies gradually died down but he has been able to breathe new life into the protest movement this year, bringing out tens of thousands of young protesters into the streets.
This year he has served three jail sentences of 15 days, 25 days and 20 days for organizing unauthorized anti-Putin protests.
The Council of Europe's decision-making body, the Committee of Ministers, has urged Russian authorities to allow Navalny to stand for election despite his "arbitrary and unfair" conviction for fraud.
Many critics scoff at Navalny's Kremlin bid but the plucky lawyer says he would beat Putin in a free election if he had access to state-controlled television, the main source of news for a majority of Russians.