Russian election officials on Monday barred opposition leader Alexei Navalny from running against President Vladimir Putin.

The Central Election Commission unanimously decided Navalny is not allowed to run in the March election because of a fraud conviction, according to the Associated Press. Navalny announced his bid for the presidency on Sunday.

Navalny and his supporters have said court cases against him are a ploy to keep him from being elected.

Putin, who is running for his fourth presidential term, is expected to win the March 18 election. Nalvany spearheaded a widespread grassroots effort this past year and posed a serious challenge to Putin.

Navalny is now calling on supporters to boycott the election.

"Going to the polls right now is to vote for lies and corruption," he said in a prerecorded message.