BERLIN – Germany’s traditionally left-leaning Greens have chosen two centrists to lead them into this year’s election, in which the party could be a key to forming a new government with or without Chancellor Angela Merkel.

Party co-chairman Cem Ozdemir and parliamentary caucus leader Katrin Goering-Eckardt won a ballot of party members, senior Green official Michael Kellner said Wednesday. Members rejected prominent left-winger Anton Hofreiter and a state-level minister, Robert Habeck.

Germany’s election is expected Sept. 24. The conservative Merkel currently governs in a “grand coalition” with the centre-left Social Democrats, an arrangement that neither partner is keen to extend, and the Greens could be a key to producing a different government.

The Greens were part of Germany’s national government from 1998 to 2005 under then-Chancellor Gerhard Schroeder, a Social Democrat.

These days, the party is divided between those who favour a coalition with Merkel and others who back a three-way left-wing alliance that would remove her from the chancellery. Both are untried at the national level, though the Greens currently are part of 11 of Germany’s 16 state governments, in a variety of different coalitions.

Both options could be complicated, and it’s uncertain at present that either will muster a parliamentary majority.

Party members in November approved a call for a wealth tax on the “super-rich,” which would clash with conservative pledges not to increase taxes. But a left-wing alliance could fail over foreign policy differences, and the choice of campaign leaders also appears to dampen its chances.

Ozdemir, 51, whose parents immigrated to Germany from Turkey, has long been a prominent figure on the party’s right. The 50-year-old Goering-Eckardt, who grew up in communist East Germany, is active in the Lutheran church and also considered a centrist.

“They are the modern Germany — both have experienced and mastered change … and fought their way through,” Kellner said.