BERLIN (AP) -- Chancellor Angela Merkel's conservatives emerged by far the strongest force in Germany's election Sunday, but their center-right coalition partners risked being ejected from parliament, exit polls indicated.
Exit polls for ARD and ZDF television put support for Merkel's conservative Union bloc at up to 42.5 percent — a gain of around 9 points from Germany's last election in 2009.
But they both put the pro-business Free Democrats just below the 5 percent needed to keep their seats in parliament — which would mark the first time in post-World War II Germany that they haven't been represented there.
Center-left challenger Peer Steinbrueck's Social Democrats trailed well behind Merkel's party with up to 26.5 percent, the exit polls showed. Their Green allies polled 8 percent, while the hard-line Left Party — with which the center-left parties have said they won't form an alliance — scored 8.5 percent.
It wasn't clear whether a new anti-euro party, Alternative for Germany, would win seats in parliament's lower house. The exit polls showed them winning up to 4.9 percent — the threshold for winning seats in 5 percent. Merkel and others have said they won't deal with the party.
If Merkel's current coalition lacks a majority, the likeliest outcome is a Merkel-led alliance with the Social Democrats. The two are traditional rivals, but governed Germany together in Merkel's first term after an inconclusive 2005 election.
A senior Merkel aide swiftly claimed the right to form the next government.
"We have a clear mandate from voters to form a government," said Volker Kauder, the leader of her party's parliamentary group. The outcome shows that "voters want Angela Merkel to remain chancellor" for a third term, he told ZDF television.
Labor Minister Ursula von der Leyen said it was an "overwhelming" result for Merkel's party. "The important thing is that Germany has stable conditions," she said.
Senior Social Democrat Thomas Oppermann said his party had expected to do better. As for the next government, he said, "the ball is in Merkel's court."
The exit polls were greeted by shocked silence at the Free Democrats' election party. "This is the bitterest hour" for the party, senior Free Democrat Christian Lindner said.
Associated Press correspondent Frank Jordans contributed to this report.