To the disheartenment of both the Social Democrats and pan-Germanic nationalists alike, the Treaty of Saint-Germain-en-Laye expressly forbade any future union ("Anschluß") with the newly founded Weimar Republic, leaving Austria with little territory and limited access to the Hungarian breadbasket that had fed Vienna for decades. In the 4 May 1919 "Gemeinderat" (en: Municipal Council) elections in the capital, the SDAP gained a majority of seats, with the office of the Mayor of Vienna won by SDAP politician Jakob Reumann. Nationally, the success of the SDAP was far less pronounced, winning only 43.4% of the seats (40.8% of the popular vote) and necessitating a coalition government with the conservative Christian Social Party (CSP), an uncomfortable position from which the SDAP would never fully succeed in overcoming.   During the Geimeinderat elections of 4 May 1919, for the first time in Austrian history, all adult citizens of both sexes had voting rights. The Social Democrats did succeed in electing prominent Austromarxist and SDAP member Karl Renner into office as the interim Staatskanzler, but after the national elections in 1920 concluded with the CSP candidate Michael Mayr succeeding Renner in his position, the SDAP did not successfully manage to elect another national-level leader for the remainder of the First Republic’s existence.