Russian billionaire Mikhail Prokhorov plans to take part in Saturday's protest in Moscow against alleged vote fraud, his spokesperson said on Friday.

Up to 50,000 people are expected to attend the downtown Moscow demonstration against suspected electoral violations in favor of Prime Minister Vladimir Putin’s United Russia party. This is the second authorized mass protest this month. A rally on December 10 drew tens of thousands and was the largest anti-government protest in Russia for some two decades.

Prokhorov plans to run against Putin in presidential elections scheduled for March 2012.

His spokesperson said Prokhorov would mingle with the crowds at the protest and would only speak if the organizers called him onto the stage, adding that the tycoon wanted to see how people "react" to him.