Yulia Navalnaya, widow of opposition leader Alexei Navalny, called on Russians to join an election day protest at noon on March 17 and to vote against President Vladimir Putin or spoil their ballots.

In a YouTube video, Navalnaya said she had drawn hope from the huge crowds that turned out last week for the funeral of her husband, who died in an Arctic penal colony on Feb. 16, and who since then have submerged his grave in a sea of flowers.

She urged people to join the March 17 action that Navalny, Russia’s best known opposition figure, had called for shortly be died. His idea was that people could register a protest, without any risk of arrest, by all turning out en masse at the same time on election day in cities across the country.

“We need to use the election day to show that we exist and there are many of us. We are real, living people, and we are against Putin. You need to come to the voting station on the same day and at the same time — March 17 at noon,” Yulia Navalnaya said.