While serving in his role for the Christian Social Party, he was, 1907, elected to the Imperial Council (Reichsrat) parliament. Re-elected in 1911, Miklas held a parliamentary seat in the provisional assembly of German-Austria and in the Constitutional Assembly of the First Austrian Republic. A rare opponent of German nationalism, he declared himself against a closer connection with the Weimar Republic and played a pivotal role in adopting the red-white-red Austrian flag.