Following a failed run for the presidency in 1996, Mikhail Gorbachev established the Social Democratic Party of Russia, a union between several Russian social democratic parties. He resigned as party leader in May 2004 following a disagreement with the party's chairman over the direction taken in the 2003 election campaign. The party was later banned in 2007 by the Supreme Court of the Russian Federation due to its failure to establish local offices with at least 500 members in the majority of Russian regions, which is required by Russian law for a political organization to be listed as a party.
Source: Wikipedia