in october 2007, kasparov announced his intention of standing for the russian presidency. in november 2007, he was detained by police at a rally in moscow and given a jail sentence of five days. on 12 december 2007, kasparov announced that he had to withdraw his presidential candidacy due to inability to rent a hall where at least 500 of his supporters could meet to endorse his candidacy, as is legally required. kasparov's spokeswoman accused the government of using pressure to discourage anyone from renting a hall for the gathering. in 2008 kasparov and his united civil front joined the solidarity movement.