In an extraordinary move, the CSU - facing a tough regional election in October - has threatened to defy her and on Monday go ahead with plans for Germany to send back migrants already registered in other European Union states.
After meeting at Chancellor Angela Merkel's Meseberg retreat outside Berlin, she and France's Emmanuel Macron presented the new budget as a means of boosting the bloc's economic competitiveness. That's fomented a deep rift between her CDU and its Christian Social Union allies, who claim they have national and EU authorization to start turning away refugees arriving on Germany's borders who first claimed asylum in other EU states.
If Seehofer actually implements it in defiance of Merkel, it could threaten the future of the government and the chancellor.
Seehofer was quoted Sunday telling the Bild am Sonntag newspaper: "No one in the CSU has an interest in bringing down the chancellor. or blowing up the coalition".
"Member States should take all necessary internal legislative and administrative measures to counter such movements and to closely cooperate amongst each other to this end", the text said in an indirect response to German Interior Minister Horst Seehofer. Merkel has asked the CSU to be patient, a request that the Bavarians have ignored.
Earlier this month, Merkel made some concessions, agreeing to support Macron's call for an investment fund to help poorer European countries catch up in the areas of science, technology and innovation.
Mr Schmieding said: "She will need a bit of a compromise here and there".
At a regular meeting of their joint Cabinets on Tuesday, Germany will seek the support of French President Emmanuel Macron to find a common European Union response for managing an influx of refugees, Merkel said Saturday in a weekly podcast.
More than 2,300 children have been taken from their parents since early May, a practice loudly decried by rights groups and United States politicians from both main parties.
The Bavarians have threatened to defy Merkel and on Monday go ahead with plans which she has sought to block.
However it ends, the spat has laid bare the limits of Merkel's authority in a fractious government that took office in March after almost six months of postelection haggling. The two parties govern with the center-left Social Democrats. In his previous job as Bavarian governor, Seehofer was one of the leading critics of Merkel's decision in 2015 to leave Germany's borders open as migrants streamed across the Balkans.
Finally, they said victims of crime are twice as likely to report incidents if they are committed by people who are different from them, distorting the statistics.
The office said 728,470 application requests were made for worldwide protection in 2017, compared to nearly 1.3 million applications the previous year.