Pro-western Ukrainians are wary of increased Russian influence in the country. In April 2010 Ukrainian prosecutors considered filing criminal charges after a parliament session in which lawmakers hurled eggs and smoke bombs and engaged in physical violence in an attempt to prevent a vote [JURIST report] on a Russian treaty. The chaos erupted as lawmakers voted to approved a treaty that extended Russia's lease on a naval base in the Ukrainian Sevastopol port on the Black Sea until 2042 in exchange for discounted Russian gas. The agreement was strongly opposed by pro-Western lawmakers who see Russian influence as reminiscent of Soviet occupation. The treaty came soon after the election of Yanukovych as President [JURIST report], who took office in February of that year. Yanukovych replaced Viktor Yushchenko [JURIST news archive], who had sought to cut ties with Russia and strengthen relationships with Western Europe. Yushchenko opposed the extension of Russia's Black Sea lease.