Russian environmentalist and protest leader Yevgeniya Chirikova had not even made it to the local election headquarters to register as a candidate on Monday before opponents ran up and showered her with fake $100 (63.36 pounds) bills as she spoke to reporters.The aim was clear: to damage her campaign to become mayor of Khimki, a town just outside northwestern Moscow, by portraying her as a tool of the United States, which President Vladimir Putin has accused of fomenting opposition to his 12-year-rule.Chirikova, one of the leading lights of protests this year against Putin, initially looked flustered as banknotes blew around her. But she soon regained her composure and laughed as her four hecklers unfurled a U.S. flag behind her and tried to push a small Stars and Stripes into her hand for the cameras.Chirikova - who has been detained, treated roughly by police and received threats on her and her family because of her environmental work - is undaunted by the threat of harassment as she joins an opposition campaign to chip away at Putin’s authority by challenging his party in local elections."The more they oppress us, the more it shows we are right to really cause them trouble,” Chirikova, 35, told Reuters before registering her candidacy in Khimki, a town of 200,000 dominated by high-rise apartment blocs. "I fear nothing. I really don’t know what could stop me now,” she said.Chirikova, who became one of the Kremlin’s most strident critics by organising protests against the construction of a road through a forest near Khimki, is the most prominent opposition politician running in local polls on October 14.Success would make little dent in Putin’s authority and that of the ruling United Russia party, but taking control of Khimki would signal that the opposition may be finally able to start building on the momentum gained in this year’s protests.