The Kremlin on Tuesday announced its desire to see Opposition Leader Alexei Navalny investigated for calling a boycott to the March 2018 Russian Presidential Election. Just hours later, hundreds of Russian celebrities, sports personalities, and politicians gathered to officially nominate President Vladimir Putin for re-election, Reuters reported. He is expected to win easily.

Mr. Navalny called for the boycott on Monday after Russian election officials barred him from from running in the election, citing his suspended prison sentence in a fraud case, a decision he has derided as politically motivated. Navalny says he now plans to use his 84 campaign offices around the country to organize the boycott and monitor polling stations. 

The 41-year-old lawyer built his political career and popularity exposing corruption at the highest levels of the Russian government, including within Putin’s own inner circle. He has railed against what he says is a kleptocracy and a fundamentally undemocratic system. In a year-long grass-roots campaign, Mr. Navalny created the most formidable opposition movement during Putin’s 18-year rule—leading the most widespread and significant protests in years and energizing opposition to the President.

Navalny responded to the ruling in an online video to his supporters. “We won’t have an election because Vladimir Putin is horribly afraid, he sees a threat in competing with me,” Mr. Navalny said in the video. “He gave an instruction to his servants from the Central Electoral Commission to reject my registration.” He insisted that in a free and fair election, he could defeat Mr. Putin.

At the Central Electoral Commission on Monday, Mr. Navalny engaged in a debate with Commission Chairwoman Ella A. Pamfilova. Ms. Pamfilova, elected in 2016 amid demands for greater fairness and transparency, argued that the commission was simply following the letter of the law. “More than anybody else we would be interested for you to run and demonstrate the result that is adequate to your popularity,” Ms. Pamfilova told Mr. Navalny. “But since there is a criminal conviction,” she said, “the commission had no choice.”

Mr. Navalny countered that his conviction had been overturned by the European Court of Human Rights. Indeed, Europe’s top human rights court ruled in October that Mr. Navalny’s 2014 conviction for fraud was, “arbitrary and manifestly unreasonable” and ordered the Russian government to pay him compensation.

In defense of the long-anticipated decision, the Kremlin has cited election polling which puts Mr. Putin far ahead of Mr. Navalny, or any other candidate for that matter. Much of the gap, according to Mr. Navalny, is due to unfair state media practices, and other efforts to suppress his message. He was arrested after organizing an anti-corruption rally in March 2017, and has been twice attacked with zelyonka, a bright green antiseptic common in Russia and Ukraine, staining his face, and requiring hospitalization for chemical burns to his eyes.

Despite these setbacks, and the recent announcement by the Electoral Commission, Mr. Navalny has vowed to continue his anti-corruption campaign against the Kremlin. However, his future is very much in doubt. Setting up the possibility of police action against Mr. Navalny and his supporters, Kremlin spokesman Dmitri Peskov told reporters in a conference call Tuesday, “The calls for a boycott will require scrupulous study, to see whether or not they comply with the law.”

The Kremlin wants high turnout in upcoming election, hoping to cement the legitimacy of what is largely expected to be a noncompetitive poll. The expected reelection of President Putin would make him eligible to serve for the next six-years until 2024, when he would be 72, though this could be extended by changes to the Constitution, a tactic Mr. Putin has utilized in the past.

For now, despite sanctions and a shrinking economy, Mr. Putin’s power seems secure. Mr. Navalny, though popular, is vulnerable, as the opposition continues to struggle to find its footing in Putin’s authoritarian Russia.