May Day was the most important event in the urban calendar, a political festival on a mass scale that validated Vienna?s status as a socialist city. Marchers converged on the city centre, led by the powerful Austrian Social Democratic Party. Grandstands were erected outside Vienna?s City Hall for music and speeches, whilst the far smaller Austrian Communist Party staged a separate demonstration in front of the Votive Church nearby. However, as political tensions heightened May Day marches became an arena of conflict, between different left-wing factions and an increasingly authoritarian national government. In May 1933, the Austrian Chancellor, Engelbert Dollfuss, banned demonstrations altogether, barricading off the centre of Vienna. Tudor-Hart was arrested shortly afterwards.