A State Duma deputy who co-authored amendments to the controversial protest law defended his position Friday, telling The Moscow Times that "those who organize meetings should be responsible for them." Vyacheslav Pozgalyov, elected to the Duma under the United Russia ticket in December, said a "third force" of ultranationalists would incite violence at upcoming demonstrations. "This force wants to provoke clashes between the current authorities and the opposition to use this wave to come to power," said Pozgalyov, 66, a career politician who was elected as a governor of the Vologda region three times. The legislator cited riots in December 2010 on Manezh Square, where more than 5,000 football fans clashed with police. "They were not doctors or lawyers, but tough guys," Pozgalyov told The Moscow Times. Under the controversial amendments, which the Kremlin reported on Friday had been signed into law, demonstrators face 300,000 ruble fines and are prohibited from wearing masks. "Tell demonstrators to take off their masks, and you will find outsiders," said Pozgalyov, referring to violent radicals outside the opposition's mainstream. Ultranationalists attend opposition rallies to push their own agenda, a right-wing party leader told The Moscow Times last month. "Let liberals shake the system. I know whom people are going to vote for," said the source, who requested anonymity to speak frankly about the movement. Pozgalyov's particular concern about ultranationalists may reveal a developing rift within the ruling elite, said Pavel Salin, an analyst at the Center for Current Politics, a think tank. "Everyone is beginning to play his own game," he said.