Flemish far-right party Vlaams Belang blocked the rue de La Loi in front of the House of Representatives, for about ten minutes on Wednesday morning, with the help of a procession of a few cars driven by deputies of the nationalist party.
The aim was to denounce the lack of government and the prospect of an "anti-democratic and anti-Flemish" Vivaldi coalition.
"If the Rue de la Loi blocks Flanders, we will block the Rue de la Loi,” the party said.
"A few more days and we are 500 days since the elections," said party leader Tom Van Grieken. "In that time, children were born, they learned to walk and even spoke their first words. We're not going to wait for them to go to school, are we?"
Several elected representatives of Vlaams Belang were preventively detained by the police in the vicinity of the Royal Palace.
A dozen vehicles, however, with the flags of Flanders in the wind, drove through the police lines before reaching the Rue de la Loi.
The party's European deputy, Gerolf Annemans, was arrested by the police during the action in front of the parliament.