"In light of authorities' negative attitude to the very existence of an independent social union of citizens, these acts by the Federal Registration Service were not unexpected for activists of the movement, " the party said in a statement posted on its website.

BBC: Mr Kasyanov is one of Vladimir Putin's rare public critics

Roza Otunbayea, leader of the Ata-Jurt (Fatherland) movement, who was denied registration as a candidate, insists that yellow is the colour: it means ready for change, she says, as in a traffic light.

ECONOMIST: Will this weekend's election bring change?