Belarus will hold its presidential election on December 19 in which long-time leader Alexander Lukashenko is expected to run for a fourth term.
All but two of the country's 110 MPs approved the date in a vote on Tuesday.
The parliament is dominated by supporters of the president.
A souring in relations with neighbouring Russia over a gas dispute could hamper his bid to secure a landslide victory.
Rights groups question whether the poll will be free and fair under Lushshenko.
He has ruled the former Soviet Republic since 1994 and was once dubbed by Washington as Europe's last dictator.