In Austria, jurisdiction in matters relating to labour and social security law falls within the system of ordinary courts. The competent courts of first instance are the Land Courts, which each act as a labour and social security court along with their other areas of jurisdiction (with the sole exception of Vienna, which has a special labour and social security court). The courts of second instance are the four Higher Land Courts, and the third and last instance is the Supreme Court of Justice. All these courts hear cases in divisions (or senates) which have, in addition to professional judges, lay judges who are nominated by the Economic Chambers and the Chambers of Labour and possess essentially the same powers as the professional judges. At the first-instance level the bench consists of one professional judge and two lay judges (one each from the employers' and the employees' side), and the second- and third-instance levels have three professional judges and two lay judges. These labour and social security courts are competent to rule on all disputes arising from labour law and all benefit claims arising from social security law. However, disputes concerning the social insurance relationship (such as disputes over the existence of an insurance relationship or obligation to pay contributions) are referred to the administrative authorities, although an appeal against a last-instance decision in such disputes may be lodged with the public-law supreme courts, and in particular the Administrative Court.