Yahoo! News, September 16, 2010: A group of Russia's most prominent opposition leaders formed a coalition Thursday to challenge the ruling duo of President Dmitry Medvedev and Prime Minister Vladimir Putin. Boris Nemtsov, who once served as deputy premier under President Boris Yeltsin, said the new coalition aims to compete in next year's parliamentary elections and field a presidential candidate in 2012. Nemtsov lambasted Putin, now prime minister, for his alleged intention to run for two more presidential terms after already serving two terms as president. Putin's hand-picked successor Medvedev also extended Russia's presidential terms from four years to six years, beginning 2012. "The prospect of having the great Putin till the year 2024 in our country is a disaster for Russia," Nemtsov said. Garry Kasparov, the chess titan who has been one of Russia's top opposition figures, was out of the country Thursday. Nemtsov said he would try to persuade Kasparov to join the coalition - Russian opposition challenges Putin, Medvedev