As an open area in the city the Hakaniemi marketplace has offered itself as a natural place for townspeople to congregate. The square has been an important rallying point for political demonstrations and marches for the labour movement. Nowadays the left alliance's May Day speeches can be heard in Hakaniemi square and the May Day processions start off from there.

     In spring 1940 the Finnish communist leaders founded the Finnish and Soviet Peace and Friendship Association. The Association was disbanded by the end of the year. The worst of its demonstrations took place on August 8, 1940, when firewood stored in piles in the square was set ablaze.