Germany's Interior Minister Horst Seehofer says the row between his Christian Social Union party and Chancellor Angela Merkel over migration policy is serious but can be overcome.
The comments suggest he will compromise to avoid a full-blown German coalition crisis.
But this weekend he was quoted in Welt am Sonntag as telling some CSU MPs: "I cannot work with the woman any more."
On Monday the CSU will decide whether to start implementing a plan drawn up by Seehofer to reject migrants who have already registered in other EU states.
Merkel opposes such a unilateralist move as it would reverse her 2015 open-door policy and undermine her authority.
The split could threaten her three-month-old coalition government and also deal a blow to the EU's Schengen open-border system at a time when divisions in the bloc are deep.
"The cohesion of Europe is at stake as well as the cohesion of Germany. The situation is serious but it can be overcome," Seehofer wrote in a guest column for the Frankfurter Allgemeine paper which was published on Sunday.
He reiterated that he wanted the right to turn people away from Germany but also stressed he wanted a European solution.
"It is crucial that the EU summit at the end of June reaches agreements that recognise Germany's burden in migrant policy," he said. The EU, he added, had to guarantee the protection of the EU's external borders, a fair distribution of people allowed to stay and the quick return of people without that right.
If no satisfactory EU deal is reached, German police would start sending back migrants registered in other EU states, it said.
If Seehofer were to defy her and go ahead with his plans on Monday, Merkel would almost certainly be forced to fire him.
There is even talk that the 70-year-old conservative parliamentary alliance between the CDU and CSU could collapse.
Without the CSU, Merkel's coalition, which also includes the Social Democrats, would lose its parliamentary majority.
While Merkel would welcome a reprieve from an immediate crisis in her coalition, she is still under intense pressure to deliver a deal with EU partners who are deeply divided.