The Russian anti-corruption activist Alexei Navalny, center, walks with demonstrators holding Russian flags during a memorial march in central Moscow on Feb. 26, two years after opposition leader Boris Nemtsov was gunned down yards from the Kremlin. (Vasily Maximov/AFP/Getty Images)

When police break up your meeting because of a false bomb threat, that could be just bad luck. When someone glues your office door shut, that could be just a misunderstanding about the rent. And when a stranger comes up to you in the street and dumps green guck all over your face, that could be just a random act of hooliganism.

When this kind of thing happens to you every day, that means you’re Alexei Navalny, Russia’s most prominent anti-corruption crusader and a declared candidate for next year’s presidential election — the mother of all uphill battles, given that your likely opponent is Vladi­mir Putin. And if you’re Alexei Navalny, there’s a good chance you’re going to wake up Monday in jail. 

Authorities have preemptively banned a rally Navalny has organized for central Moscow on Sunday, as well as others planned across Russia. The demonstrations were called to protest what he claims is rampant corruption in the Kremlin. Putin’s spokesman has said that even urging people to take part is illegal.

And Alexander Gorovoi, a senior Russian police official, warned Friday that authorities will “bear no responsibility for any possible negative consequences” for people who do show up. That could mean that if something is started by pro-government activists who routinely interfere with Navalny’s campaign stops, officers might stand aside and let it happen.

Navalny, who has been arrested several times over the years, said the rally will go on. 

In this photo provided by Alexei Navalny, the Russian activist appears in a selfie with supporters after an unknown assailant sprayed a green antiseptic on his face in Barnaul, Russia. Navalny was in the city to open a campaign office as part of his bid for the presidency in 2018 elections. (Alexei Navalny/AP)

“The Kremlin sees us as their enemy, but what should I do?” he said Thursday in his Moscow headquarters. “I’m not going away. I live here. I’m going to live here.”

What Navalny has done to provoke official enmity is issue frequent statements alleging instances of top Kremlin officials amassing huge fortunes. Most recently, he released a report and a 50-minute video detailing allegations that Prime Minister Dmitry Medvedev has funneled more than $1 billion in bribes through companies and charities run by his associates to acquire vineyards, luxury yachts and opulent mansions.

The Russian government has barely acknowledged those accusations. One lawmaker in the State Duma, a Communist, asked for an inquiry into Navalny’s report. Otherwise, the only palpable reaction has been that when the activist appears in public, eggs are tossed in his face, activists from the pro-government National Liberation Movement shout down his speeches and occasionally he is doused with a green, Soviet-era topical antiseptic known as zelyonka.

But that is shaping up to change Sunday when Navalny and his supporters — he anticipates tens of thousands — plan to challenge the bans on their rallies in Moscow and across the country.

In an interview Thursday, during a rare stop in Moscow, Navalny argued that staging the protests is worthwhile, despite the likelihood he will be arrested, because it will signal the breadth of the support for his message — that Russia needs to rid itself of what he sees as a kleptocratic and authoritarian regime. People in 100 Russian cities have indicated they will turn out Sunday, he said, and more than 10 million people have watched the YouTube video about Medvedev.

“I know that I represent millions of people, I know that my positions are supported by the people, and if it were an honest election, I’d win,” he said, noting that he is denied access to state-run television coverage as well as the right to legal assembly.

 Putin’s spokesman, Dmitry Peskov, dismissed the idea of an official campaign against Navalny. 

“This issue has nothing to do with us or our agenda,” he said in a text message, referring to Navalny’s candidacy and perceptions of harassment.

Technically, Navalny is barred from running for president because of a February conviction and a five-year suspended sentence in an embezzlement case. The verdict echoed the one returned in a 2013 trial on the same charges and overturned after the European Court of Human Rights declared it “prejudicial,” saying that Navalny and his co-defendant were denied the right to a fair trial.

Even if Navalny were allowed to run, he would be a decided underdog to Putin, who has enjoyed an approval rating above 80 percent for the past three years. Lev Gudkov, director of the Moscow-based Levada Center, which tracks Putin’s rating, said in a recent interview that Navalny could probably win about 15 percent.

That’s not much of a threat, except when you consider that Russian Communist leader Gennady Zyuganov and the ultranationalist Vladi­mir Zhirinovsky are likely to run, splitting something like 20 percent of the vote between them, Gudkov said. 

According to Gudkov and other analysts, the Kremlin is thought to be looking for at least 70 percent of the vote as a validation of Putin’s continued rule. 

“The elections will be more like a plebiscite of confidence in Putin,” said Andrei Kolesnikov, a senior associate at the Carnegie Moscow Center, who suggested that anything more than 60 percent would be pushing the upper limits of Putin’s real electoral rating.

Unlike the support for Zyuganov, Zhirinovsky and the probable liberal candidate, Grigory Yavlinsky, who have all been running for president since the mid-1990s, the wave of political activity that Navalny is creating “makes him more of a danger for the Kremlin,” Kolesnikov said.

Being a threat to the establishment has been a hazardous profession in Russia; Ukrainian officials called the shooting of a Putin critic, Denis Voronenkov, in Ukraine on Thursday “state terrorism.” In Russia, opposition leader Boris Nemtsov was gunned down in 2015 outside the walls of the Kremlin, one of a list of prominent critics who died suddenly.

The Kremlin has strongly denied involvement in any of those deaths. 

Navalny says he understands the danger of his position. He said he used to have a bodyguard but decided there was no point — if someone powerful wanted him dead, a bodyguard wouldn’t be enough to save him.

“It doesn’t guarantee your safety,” he said. “It’s an arms race I can’t win.”