But its real purpose, it seems, is to act as a spoiler for the Communist Party and another party, JustRussia, which itself was originally created as a double for United Russia but has since become a genuine challenger.
At another square in Moscow, Communist, AJustRussia, and the nationalist Liberal Democratic Party will all meet with their respective candidates to protest Putin.
The walkout by AJustRussia came after Mr Putin said Oleg Shein, the party's mayoral candidate in the city of Astrakhan, should have gone to court instead of launching a hunger strike.