BERLIN (AP) — The leader of Chancellor Angela Merkel's center-right party warned Sunday that Germans risk ending up with a very left-wing government if they vote for the Greens, who surged in last month's European Parliament election and are now level with or ahead of Merkel's Union bloc in several polls.

The Greens traditionally leaned left but in recent years have formed regional coalitions with Merkel's Christian Democratic Union in several states. Last week, however, they rejected the chance to do so in Germany's smallest state, Bremen, and opted for a coalition with the center-left Social Democrats and the hard-left Left Party.

CDU leader Annegret Kramp-Karrenbauer told the Bild am Sonntag newspaper that events in Bremen show that "people who dream of a new government and vote Green must know that they could wake up with the Left Party."

Merkel's Union bloc currently runs Germany in a "grand coalition" of what were traditionally Germany's biggest parties with the Social Democrats. But in the May 26 European vote, both partners had their worst showing in a nationwide election since World War II, and the Greens overtook the Social Democrats to finish second behind the Union — fueled by concern that other parties aren't doing enough about climate change.

The election battering triggered the resignation of the Social Democrats' leader and reignited speculation that the governing coalition could collapse within months, likely resulting in an early national election. It's unclear what coalitions would then be possible, but likely that the Greens might be needed to form one.

Merkel has said she won't seek another term, and Kramp-Karrenbauer has had a bumpy start since succeeding her as party leader in December. Polls since the European election have shown the Greens surging further and party co-leader Robert Habeck's popularity rising.

Asked about the Greens' climate policy, Kramp-Karrenbauer replied that "excessively radical measures could divide the country" and called for "determined but acceptable steps."

"It is the core responsibility of the CDU to shape climate protection in such a way that it is acceptable for all citizens," she was quoted as saying.

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