Kremlin critic and former world chess champion Garry Kasparov will not run in Russia's presidential election after authorities repeatedly blocked supporters' efforts to hold a nominating conference, his spokeswoman said Thursday. Under election law, Thursday is the last day that potential candidates for the March 2 vote have to hold such conferences. A spokeswoman for the broad-based opposition coalition that Kasparov heads told The Associated Press that organizers have been unable to find an auditorium or hall in Moscow where activists could gather and vote to put forth Kasparov as a candidate. Spokeswoman Marina Litvinovich accused the government of pressuring landlords to not rent to the coalition, Other Russia. "Authorities put up as many obstacles as possible to stop us. That's it," she said. Since leaving chess, Kasparov has become a vociferous critic of President Vladimir Putin's government, cobbling together a disparate coalition of nationalists, left-wing activists and liberals to try to generate broad opposition. Authorities have repeatedly stymied protest marches in major Russian cities, often violently breaking up demonstrations. Kasparov was detained for five days last month after a protest in Moscow.