The co-leader of nationalist party Patriotic Front Valeri Simeonov described Bulgarians living abroad who protested against the new restrictions on polling stations as "a handful of Sorosoids".
Bulgarian nationals living abroad held demonstrations in several European cities to protest government plans to ban the opening of polling stations outside diplomatic missions.
Earlier Mr Simeonov was involved in a row with a Bulgarian activist living in the United States campaigning against the amendments to whom he had sent a letter suggesting she should stop pestering MPs as they were trying to work on "serious" issues.
The comments by Valeri Simeonov sparked continuous demonstrations and a domestic outcry.
Under the initial proposal, voting abroad could only take place in diplomatic missions, but the ruling axis backtracked.
