berlin chancellor angela merkel efforts forge three-way rule coalition drag wee hours friday participants warn differences climate migration finance could still cause talk collapse conservative leader set thursday deadline exploratory talk form coalition pro-business free democrats fdp environmentalist green combination untested national level would allow govern fourth term german chancellor merkel 63 tell reporters thursday serious differences remain talk could take many hours participants gird marathon session german media call night long knives mood sour noticeably late thursday party break huddle respective caucus senior negotiators resume tough discussions migration senior fdp official alexander lambsdorff describe serious face post twitter fdp deputy leader wolfgang kubicki suggest extension talk might need conservative participants concede talk go well green bavarian wing conservatives christian social union csu even accuse block agreement juergen trittin green negotiator use twitter illustrate view state talk clip reggae star jimmy cliff sing hard come hard fall one failure clinch deal could lead new elections scenario none negotiate party want fear far-right alternative germany afd could make gain surge parliament sept. 24 national vote outcome would see so-called black swan event could weigh heavily euro merkel try break logjam least climate protection offer reduce coal power generate capacity gigawatts gw source familiar talk say still shy 10 gw cut demand green early offer gw chancellor pressure conservative bloc particularly csu compromise much secure coalition deal especially migrants csu fear lose grind 2018 state election stake conservative plan cap number people germany accept per year humanitarian ground 200,000 limit environmental green reject know resolve discrepancies disagreements say joachim herrmann senior member csu sister party merkel christian democrats cdu fdp secretary general nicola beer twitter post urge side remain open compromise ask counterpart something give otherwise get nothing end merkel skilled negotiator renowned european union summit build pressure negotiate partner play fatigue must leverage skills secure three-way jamaica coalition call party color match caribbean island country flag failure jamaica would failure write mass-circulation daily bild merkel partner germany previous grand coalition center-left social democrats spd vow return opposition suffer bad election result since 1933 september national vote alice weidel co-leader far-right afd criticize would-be coalition partner fail reach deal tell daily die welt conservative union fdp green reach agreement soon new elections negotiators agree deal thursday talk must still pass muster lower-ranking party officials key test would green conference nov. 25 party rank file would examine coalition pact german coalition talk flounder disagreements persist