The political system of the Second Republic is based on the constitution of 1920 and 1929, which was reintroduced in 1945. The system came to be characterised by ''Proporz'', meaning that most posts of political importance were split evenly between members of the Social Democratic Party of Austria (SPÖ) and the Austrian People's Party (ÖVP). Interest group "chambers" with mandatory membership (e.g. for workers, business people, farmers) grew to considerable importance and were usually consulted in the legislative process, so hardly any legislation was passed that did not reflect widespread consensus.