berlin germany social democrats spd beat angela merkel conservatives vote northern state low saxony sunday setback chancellor prepare tricky three-way coalition talk national level week spd govern swing state home carmaker volkswagen vowg_p.de green four years 37.5 percent well 32.6 percent last election 2013 accord exit poll infratest dimap merkel christian democrats cdu fetch 35 percent vote rich agricultural state 36 percent last election 2013. environmentalist green currently junior coalition partner spd low saxony 8.5 percent liberal free democrats fdp percent far-right alternative germany afd clear 5-percent threshold enter parliament 5.5 percent merkel conservatives score bad result since 1949 september national election begin exploratory discussions fdp green berlin week seek cobble together federal government germany 's social democrats beat merkel 's conservatives state vote