President Alexander Lukashenko called opposition leaders "cowards" after they urged people to boycott an election that looks set to reinforce the hardline leader's grip on the former Soviet country.
"They are cowards who have nothing to say to the people," Mr Lukashenko said after voting at a Minsk polling station. Preliminary results are expected today.
The two main opposition parties see the election as a sham exercise to produce a 110-seat chamber which will rubber-stamp Mr Lukashenko's directives. The United Civic Party and the Belarusian People's Front said anyone voting in the poll would be casting a ballot for his leadership as a whole and would be validating the detention of political prisoners and election fraud.
Western monitoring agencies have not judged an election in Belarus free and fair since 1995. The Organisation for Security and Co-operation in Europe has fielded 330 observers for the election and is expected to give its verdict on the polls.