Alexey Navalny’s team is used to working independently. The most potent foe of Russian President Vladimir Putin was frequently absent for long stretches after being arrested, assaulted, poisoned, or imprisoned.

But when Navalny died suddenly in February at age 47 in a remote Arctic prison, his team was left with a monumental challenge: sustaining an opposition movement against Putin — who is all but certain to be reelected — without the living example of their defiant and charismatic leader.

After the initial shock wore off, Navalny’s closest allies returned to the work that cost Navalny his freedom and life: undermining Putin’s iron-fisted grip on power.

A significant test will come Sunday, the last of three days that voters can go to the polls in an election that is widely viewed as more of a formality than an exercise in democracy.

That’s when Navalny’s team — with the endorsement of his widow, Yulia Navalnaya — is calling for a protest dubbed “Noon Against Putin.” They are asking Russians to flock to polling stations Sunday at noon local time across the country’s 11 time zones to demonstrate their discontent with Putin’s rule and his war against Ukraine.

“It is a very simple and safe action, it can’t be banned,” Navalnaya said in a video address. “It will help millions of people to see their like-minded allies and to realize that we are not alone, we’re surrounded by people who are also against the war, against corruption and against lawlessness.”

Yulia Navalnaya, the widow of Alexey Navalny, addresses the European Parliament, in Strasbourg, France, Feb. 28, 2024. She and other Navalny followers are asking Russians to flock to polling stations at noon Sunday to show their discontent with Putin.

Yulia Navalnaya, the widow of Alexey Navalny, addresses the European Parliament, in Strasbourg, France, Feb. 28, 2024. She and other Navalny followers are asking Russians to flock to polling stations at noon Sunday to show their discontent with Putin.

Navalny’s followers have expressed a wide mix of emotions in the weeks since his death, from renewed inspiration to a sense of defeat.

Maria Obukhova of Moscow, who paid tribute to Navalny on Wednesday at the Borisovskoye Cemetery, said the crowds she saw at his funeral — which numbered in the thousands — were motivational.

“It was a huge surprise for me, because it seemed before like everything had died here, that Russia is no longer, that it had died,” said Obukhova, who placed white daisies at Navalny’s gravesite.

Another Muscovite at the cemetery, a man named Valery who withheld his last name for security reasons, said he had little hope for the future and that after Navalny’s death, “something has really broken” inside of him.

Just several days after her husband’s death, Navalnaya expressed determination to keep his mission alive.

In the past month, she has addressed the European Parliament, met with United States President Joe Biden, and urged Western countries not to recognize the results of Russia’s election. She also has called on the West to impose more sanctions on those close to Putin.

Leading up to the election, Navalny’s team urged supporters to cast their ballots for any candidate other than Putin, or to invalidate them by choosing two or more candidates. They also had dozens of volunteers call ordinary Russians to ask them about their grievances and try to turn them against Putin.

The phone campaign was announced by Navalny over the summer, and since then “tens of thousands” of calls were made, Leonid Volkov, Navalny’s top strategist, said a video. “We will not stop doing that,” he vowed.

Volkov also gave a video address shortly after Navalny’s death to rally supporters and perhaps tap into his longtime ally’s spirit of persistence. “It will be a monument to Alexey’s cause if you and I live to see how this regime disintegrates before Putin’s eyes,” he said.

People vote in Russia's presidential election in the Russian-controlled area of the Donetsk region of Ukraine, March 15, 2024.

People vote in Russia’s presidential election in the Russian-controlled area of the Donetsk region of Ukraine, March 15, 2024.

Still, the Putin opposition’s uphill battle has only gotten steeper with its leaders in exile.

“(Putin’s) regime pushes people out of the country because it understands very well that the possibilities of influencing political processes in Russia from abroad are minimal,” said Nikolay Petrov, a visiting researcher at the German Institute for International and Security Affairs.

Sunday’s “Noon Against Putin” protest will be a test of how much Navalny’s team can do in Russia from abroad, said Sam Greene, a director at the Center for European Policy Analysis in Washington.

“One part of what they want to do is to send a message to those who remain in Russia that you’re not alone, that the opposition in exile has their back to a certain extent and will support them,” said Greene. “But then the question is, how do they support them?”

Efforts are underway to disrupt the protest. Navalny’s team said fake emails have been sent around purporting to be from them telling Putin opponents to show up at the polls at 5 p.m. instead of noon.

Russia’s independent election watchdog, Golos, reported that officials in at least one region are being instructed to report large gatherings near polling stations to the police.

On Thursday night, the Prosecutor’s Office in Moscow warned that unauthorized rallies near polling stations “may prevent citizens from freely exercising their voting rights and the work of election commissions,” a criminal offense punishable by up to five years in prison.

FILE - Leonid Volkov, who has served as Alexey Navalny's top strategist, speaks during an interview at the European Parliament in Strasbourg, France, Dec. 14, 2021. On Tuesday, Volkov was attacked near his home in Lithuania.

FILE – Leonid Volkov, who has served as Alexey Navalny’s top strategist, speaks during an interview at the European Parliament in Strasbourg, France, Dec. 14, 2021. On Tuesday, Volkov was attacked near his home in Lithuania.

The personal risks for Putin’s opponents remain high.

On Tuesday, Volkov was attacked near his home in Lithuania. Assailants smashed a window of his car, sprayed tear gas into his face and beat him with a hammer, according to Navalny’s team.

Volkov was taken to a hospital, and upon release said his arm was broken and his leg was injured so much it was painful to walk.

He accused “Putin’s henchmen” of the attack and said it was an attempt to intimidate the team ahead of the “Noon Against Putin” protest.

With Navalny gone, some of his supporters are recalibrating their expectations.

Valery, one of many people who visited Navalny’s grave in southeastern Moscow in recent weeks, said he is less optimistic about the opposition’s prospects going forward.

“Even though Yulia, his wife — his widow — has picked up the baton, I’m not sure that it is going to be the same as it was when Alexey was alive,” he said.