– As German Chancellor Angela Merkel racks up praise abroad for welcoming migrants, she's headed for a reality check from her political base at home.

A convention of Merkel's Christian Democratic Union starting Monday will take up motions to restrict the biggest influx of asylum seekers since World War II, defying the chancellor's open-door stance. That policy led Time magazine to name Merkel its Person of the Year and prompted a swell of praise from well-wishers on Twitter, including President Obama and Hillary Clinton.

While polls suggest that Merkel retains overwhelming support in her party, many of its members are urging a cap on the number of migrants allowed into Europe's biggest economy. After months of record inflows, this year's arrivals reached 1 million this week.

"We also have a responsibility to our country and our citizens, whose capacity to bear burdens isn't unlimited," the party's youth organization said in a resolution to be debated at the two-day meeting in the city of Karlsruhe. The measure advocates a cap.

Merkel's insistence that Germany has an obligation to feed and shelter people fleeing war and oppression is colliding with resistance within her coalition and among state governments and local officials who say towns and cities are near the breaking point.

Two other groups within the party, a caucus representing Germany's small and midsize Mittelstand companies and a lobby for local governments, are also urging changes, including measures to dissuade migrants from heading to Germany through the Balkans.

That adds to demands by Bavarian Premier Horst Seehofer, the chairman of the Christian Social Union, to limit migration. He isn't backing down even after Merkel pledged to reduce the influx, foremost by securing the European Union's outer border and enlisting Turkey's help in stemming the flow. Seehofer will address the convention on Tuesday.

The Bavarian's public rebuke of Merkel at a party convention in November will probably strengthen his bigger sister party's resolve. With no obvious successor after 10 years in power, Merkel's has a reservoir of political capital to expend on the migrant crisis.

"She's been so firm on this that she cannot roll back," said Andrea Roemmele, a political scientist at the Hertie School in Berlin. "She'll stand by her position."

The CDU national leadership's lead motion, presented Thursday, advocates controlling and reducing the influx, while avoiding any reference to a limit. That's in line with the Social Democratic Party, Merkel's junior coalition partner, which criticized a cap as xenophobic.

"We'd have to put a fence around the border and deploy the military with bayonets," Socialist Democratic leader Sigmar Gabriel, Merkel's vice chancellor, told a convention in Berlin on Thursday. "We will never do that, ever."

Support for Merkel's bloc declined 1 percentage point to 38 percent in a weekly Forsa poll published Wednesday. While that compared with a level of 43 percent in mid-August, it understates the broad support Merkel enjoys within the CDU, Forsa managing director Manfred Guellner said.

"The critics of Merkel's refugee policy are the outliers," Guellner said. "The majority of the party is much more open-minded."