(Adds quotes from president and opposition) By James Kilner TBILISI, Nov 10 (Reuters) - A Georgian billionaire accused of plotting a coup declared on Saturday he would run in next year's presidential election, providing the opposition with a potential high-profile figurehead. A 10-party coalition is looking to rally around a single leader to challenge U.S.-ally President Mikhail Saakashvili, whom they accuse of corruption and economic mismanagement. Saakashvili called an early election on Jan. 5 after he ordered police to drive anti-government protesters off Tbilisi's streets earlier this week and imposed a state of emergency. Billionaire financier Badri Patarkatsishvili is a prominent but controversial opposition figure in Georgia, which is experiencing one of its worst political crises since a civil war in the early 1990s. "I have decided to participate in the presidential election," Patarkatsishvili said in an e-mailed statement. "Mr Saakashvili's regime has completely discredited itself in the eyes of the Georgian people who will never again entrust it its destiny." He said he would withdraw from the election if the opposition united behind another leader. Analysts have said Saakashvili's opponents could find it difficult to promote a leader with enough charisma to challenge him and opposition leaders said they had not yet chosen a candidate. "Badri Patarkatsishvili is not an issue for us right now," opposition leader Tina Khidasheli told Reuters. She said they would wait until the state of emergency was repealed before announcing their candidate. Saakashvili said a state of emergency was necessary because Russian agents were destabilising the country, an allegation that Moscow denies. He has aggressively pursued a pro-Western agenda since sweeping to power in a peaceful 2003 revolution. OWNS SOCCER CLUB On Friday, the prosecutor-general's office accused Patarkatsishvili -- an associate of Russian exile Boris Berezovsky who has advocated revolution in Russia -- of plotting a coup and said it wanted to question him. The silver-haired moustachioed Patarkatsishvili, who owns a Tbilisi soccer club and made his cash in Russia during the chaotic 1990s, lives mainly in London and is not currently in Georgia. "My election slogan will be 'Georgia without Saakashvili is Georgia without Terror'," he wrote. Georgia lies at the heart of the volatile Caucasus region -- an east-west transit route that is wedged between Russia and the Middle East and hosts a pipeline pumping oil from the Caspian Sea to Europe. After police with batons chased protesters through the streets of Tbilisi on Wednesday, they raided Georgia's main independent broadcaster -- in which Patarkatsishvili is the majority owner -- and pulled it off the air. Saakashvili wants Georgia to join both NATO and the European Union and the West had held his administration up as a beacon of liberal, democratic reform in the former Soviet Union. On Saturday, he underlined that, despite street life in Tbilisi returning to normal, he would not be pushed into ending the state of emergency before he felt the time was right. "I'd like to tell our friends as well as ill-wishers that I will not lift it under anybody else's instruction," he told Georgian business leaders in a speech. (Additional reporting by Michael Stott; editing by Andrew Dobbie)
