Russia's upper house of parliament will on Dec. 13 officially announce the date of the March presidential election, Communist Party leader Gennady Zyuganov said on Tuesday – a step that marks the start of overt campaigning.

According to Russian law, the upper house of parliament must announce the exact date at least 100 days before the vote. Election day is widely assumed to be March 17.

President Vladimir Putin has not yet said whether he plans to run again, although it is generally expected that he will do so, and win.

"According to my information, the Federation Council will on Dec. 13 officially announce the start of the presidential election campaign," Zyuganov said.

Zyuganov said the ruling United Russia party would hold a conference on Dec. 17 and the Communists on Dec. 23.