Thousands of Belarussians have staged the largest opposition rally in years on the eve of an election, with the president threatening protesters. Alexander Lukashenko, accused in the West of human rights violations in 12 years in power, is all but certain to easily defeat three challengers, two from the small liberal opposition.Alexander Milinkevich, the main opposition hopeful, accuses Lukashenko of preparing to rig the vote. The European Union, which has sanctions in place against Belarussian officials, expressed concern over a "lack of freedom". About 6000 people massed on the outskirts of the capital, Minsk, for a rock concert, waving the EU flag and the traditional red-and-white national colours banned by Lukashenko. Those in attendance chanted "Freedom!" and "Long Live Belarus!" Milinkevich told supporters to take to the streets after the polls closed, as Ukrainians did in the 2004 Orange Revolution, to keep the count honest despite official warnings that public order violations would be treated as terrorism.