The march was scheduled to coincide with the opening of the new Riksdag session during which the measure, which gives expanded telecommunications monitoring powers to Sweden’s National Defence Radio Establishment (Försvarets Radioanstalt – FRA).
Banners held aloft during the march included messages such as “Centre-right No to the FRA-law”, “Stop the FRA-law now!”, and “Do you want it like Soviet times?”.
The protest also featured speeches from a number of prominent opponents of the law, including Liberal Party (Folkpartiet) Riksdag member Birgitta Ohlsson.
“Tear it up, start over, and set up a parliamentary committee,” she said in her speech.
The Riksdag’s new session otherwise began as tradition dictates, on the third Tuesday in September, with gathering and roll call of Riksdag members.
The opening ceremonies will officially begin at 2pm in the main chamber with invited guests joining a rendition of the King’s Song, a tune paying tribute to Sweden’s monarchy.
Prime Minister Fredrik Reinfeldt will then give his inaugural address to members and the Speaker of the Riksdag in which he presents the government’s priorities for the coming year.