Addressing supporters, Kasyanov said his movement -- the Popular Democratic Union (NDS) -- would fight "for honest and fair elections" and strive to prevent the authorities from rigging votes.
Kasyanov also said his party would consult with other political forces with a view to drafting a long-term development program for Russia.
Kasyanov last December failed to win over the leadership of the Democratic Party.
(RIA Novosti, ITAR-TASS, lenta.ru)