BERLIN - German Chancellor Angela Merkel urged her supporters to keep up the momentum in the final hours before Sunday's national election, urging a last push to try to sway undecided voters.

Merkel is seeking a fourth term in office and her conservative bloc of the Christian Democratic Party and Bavarian-only Christian Social union has a healthy lead in the polls. Surveys in the last week show it leading with between 34 to 37 percent support, followed by the Social Democrats with 21 to 22 percent.

Still, the support has been gradually eroding over the past week. Merkel told supporters in Berlin on Saturday that they needed to keep up their efforts to sway undecided voters, saying "many make their decision in the final hours."

After handing out coffee and chatting with the campaign workers in Berlin, Merkel headed north to her own riding, walking through the streets of the city of Stralsund shaking hands, posing for photos and signing autographs.

She also campaigned in the northern city of Greifswald and planned a stop as well on the island of Ruegen in the Baltic.

Her main challenger, Social Democrat Martin Schulz, was in western Germany at a rally in the city of Aachen.

At a rally Friday night in Berlin, Schulz urged Germans not to vote for the anti-migrant Alternative for Germany party, known by its German initials AfD, which appears assured of gaining seats in the national parliament for the first time. The nationalist party has 10 to 13 percent support in the polls.

Calling the AfD a "party of agitators" and "the enemies," Schulz said his Social Democrats were the best option to fight them.

"We will defend democracy in Germany," he said.

In addition to the AfD, the Greens, the Free Democratic Party and the Left Party were all poised to enter parliament with poll numbers between 8 and 11 percent.

With the numbers so close, several different coalition government combinations could be possible. Merkel on Friday night told supporters in Munich not to be complacent with her bloc's lead.

"We don't have a single vote to give away," she said. "We can't use any experiments - we need stability and security."