Germany’s Green party, the most electorally successful of its kind in Europe, may enter a coalition with Chancellor Angela Merkel’s conservatives after next year’s parliamentary election.

Although the Greens would prefer an alliance with the Social Democrats, with whom they governed the country between 1998 and 2005 under Gerhard Schröder, opinion polls suggest that the two left-wing parties may not gather the necessary majority. The Social Democrats are languished at 30 percent in preelection surveys compared to 39 percent for Merkel’s Christian Democrats. Pollsters put support for the Greens at 13 percent, up from 11 in the last federal election.

Once a far-left pacifist movement, Bündnis 90/Die Grünen has transformed itself into a moderate, on some issues even conservative, environmentalist party in recent years. It joined a coalition of conservatives and liberals in the Saarland legislature and even won the prime ministership in Baden-Württemberg, once a conservative stronghold, where they govern with the Social Democrats. The party elected a centrist candidate, Katrin Göring-Eckardt, to the party leadership this month who is expected to siphon off votes from Merkel’s conservatives.

Many Green party members are still skeptical about a coalition with the right on the federal level. So are many conservatives. Even if Merkel has robbed them of one of their most defining positions, opposition to nuclear energy, the chancellor could well prefer a broad coalition with the Social Democrats with whom her European and economic policies are more aligned.

A continuation of the conservative-liberal coalition seems unlikely. The Free Democrats have performed poorly in recent state elections and might not even make the election threshold in September of next year when a federal elections is expected to be called. Liberal party voters have defected either to Merkel’s Christian Democrats, who are also fiscally conservative, or the Green party, which is also socially liberal.