Kasparov is a leading force behind Other Russia, a coalition which unites liberals, leftists and nationalists who oppose Russian President Vladimir Putin.

The Russian constitution requires Putin to step down after serving two four-year terms. His has yet to endorse a potential successor, but his approval is seen as pivotal to the upcoming elections, which will be held in March 2, 2008.

Kasparov's coalition has little public support

Kasparov, 44, won 379 of 498 votes at Other Russia coalition's national congress. Yet Kasparov's place on the March ballot remains uncertain. His candidacy needs to be registered and will likely be blocked.

Even if he is allowed to run, Kasparov is not expected to pose a major threat to Putin's candidate. While Kasparov is well known in Europe for his chess exploits, the latest poll by the independent Levada news agency shows 3 percent of Russians will vote for the Other Russia candidate.

"The goal of the Other Russia is not winning elections, but to have an election," Kasparov said, speaking in English on the sidelines of the congress. "We're trying to force the regime to accept our right to participate in free and fair elections, to agitate the Russian population and the Russian public to support our ideas."

Kasparov calls for unity in opposing Kremlin

Kasparov says that Putin's broad public support comes from the Kremlin's control over the media and the electoral process.

"I will do everything possible for the ideas of Other Russia to win. This will work only if we stay united," Kasparov said, adding the coalition stood for a "democratic and just Russia."

The Other Russia coalition is hampered by internal divisions and has been marginalized by the authorities. Kasparov founded the coalition in 2005 after a successful chess career.

Kasparov faces challenge of his career

Kasparov is fond on comparing current political battles to his famous duels with Anatoly Karpov in the 1980s.

"Back then, the chess system wanted to maintain a cosy status quo, avoiding any candidate worthy of the name to fight Karpov," he has said. "The political situation in Russia today reminds me of that time."

Kasparov was born in the former Soviet republic of Azerbaijan to Armenian-Jewish parents. He took up chess in 1963 at the age of 6 and was a junior champion by the age of 13. He became the world's youngest chess champion when he beat Karpov in 1985 at the age of 22.

Political maneuvering underway

There could be surprise contenders in the race, First Deputy Prime Minister Dmitry Medvedev said on Sunday. Medvedev, who also chairs gas monopoly Gazprom, has ruled out running for parliament as a pro-Kremlin party candidate, but did not answer direct questions about whether he would run for president. Medvedev, 42, is one of a small group of Kremlin insiders who has been tipped as a possible successor to Putin.

Putin has not ruled out returning to power in 2012. He has kept everyone guessing about which candidate will get his crucial endorsement. He surprised observers by appointing Viktor Zubkov, a relatively unknown 66-year-old former head of an anti-money laundering unit, as prime minister on Sept. 14.

Putin, 54, has said Zubkov is one of five people who could succeed him, but so far has kept mum on the names of the others.