Russian opposition leader Alexei Navalny has been thwarted in his bid to challenge President Vladimir Putin in the 2018 elections after he an electoral commission ruled him ineligible to stand.

The Central Election Commission (CEC) refused to register Mr Navalny as candidate in the 2018 presidential race, citing his criminal conviction in a controversial embezzlement case, which, according to Russian laws, precludes him from running for public office.

Mr Navalny has dismissed the conviction as politically motivated.

Twelve members of the Commission out of 13 voted against registering Mr Navalny’s candidacy, in a ruling that came just a day after he was endorsed by more than 15,000 people.

Mr Navalny, who was present at the vote, argued that his conviction was overturned by the European Court of Human Rights earlier this year. He added that he represents “a huge number of voters,” and not allowing him run will “exclude millions of people out of this election.”

“I understand the difficult position you’re in, but at least once in your life you should be able to do the right thing,” the politician was quoted by the RBC news outlet as saying.

He said he would appeal the ruling which was "not against me, but against 16,000 people who have nominated me, against 200,000 volunteers who have been canvassing for me."