Soon after the announcement, the anti-government youth movement Otpor! led the campaign to topple the administration and introduce a transparent democracy. To unify opposition, eighteen parties in Serbia formed the Democratic Opposition of Serbia (DOS) coalition, with Vojislav Koštunica as the candidate to confront Milošević. Apart from this, two major opposition parties, Serbian Radical Party and Serbian Renewal Movement also had candidates (Tomislav Nikolić and Vojislav Mihailović, respectively), but the main battle of the elections was the one between Milošević and Koštunica. The election campaign lasted for about two months and was extremely tense, with numerous incidents, accusations of treason, independent media shutdowns and even murders.