BRUSSELS – The European Union’s top diplomat warned on Tuesday that Russia’s decision to ban a prominent opposition member from running in next year’s presidential elections cast serious doubts on how democratic the vote would be.

The Russian Central Election Committee had on Monday decided to bar Alexei Navalny from participating in the March 2018 election due to past convictions for embezzlement, which he claims were politically motivated.

The decision to bar him “casts a serious doubt on political pluralism in Russia and the prospect of democratic elections next year,” said a spokesperson for Federica Mogherini in a statement.

The European Court of Human Rights had ruled that Navalny had not received a fair trial when he was charged with embezzlement in 2013 for allegedly conspiring to steal timber from a state-owned company.

When the case was reviewed in 2017, Navalny was again found guilty by a Russian court, though he pointed out that all the court’s documents were identical to those used in 2013.

“Politically-motivated charges should not be used against political participation,” said the spokesperson’s statement.

Mogherini’s office said it expected Russian authorities to ensure the elections were fair and the Organization for Security and Cooperation in Europe to be invited to send observers to the vote.

Navalny urged Russians on Monday to boycott the elections after accusing President Vladimir Putin of ordering the CEC to block his candidacy.