A combination of file photos of top candidates in the upcoming German general election German Chancellor and head of the Christian Democratic Union (CDU) Angela Merkel; Peer Steinbrueck of the Social Democrat (SPD); Rainer Bruederle of the Free Democratic Party (FDP); Juergen Trittin of the Green Party (Die Gruenen)and Katrin Goering-Eckardt of the Green Party (Die Gruenen). With her conservatives far ahead in opinion polls, Germany's Angela Merkel is expected to remain chancellor after a federal election on September 22, 2013. But in all likelihood, she will need to form a coalition with another party in order to extend her rule. Merkel would like four more years in a centre-right coalition with the business-friendly Free Democrats (FDP) but recent polls suggest a 'grand coalition' with the Social Democrats (SPD), like her first government from 2005-2009, is more likely. REUTERS/STAFF/files (GERMANY - Tags: POLITICS ELECTIONS)