Alexander Dobrindt said Germany could no longer show the world a "friendly face" - a phrase used by Merkel as refugees began pouring into Germany last summer - and that if the number of new arrivals did not drop soon, Germany should act alone.
"I urgently advise: We must prepare ourselves for not being able to avoid border closures," Dobrindt, a member of the Bavarian Christian Social Union (CSU), told the Muenchner Merkur newspaper.
The CSU, the Bavarian sister party to Merkel's conservative Christian Democrats (CDU), has ramped up pressure on the chancellor over her open-door refugee policy that saw 1.1 million migrants arrive in Germany last year alone.
CSU leader Horst Seehofer told Der Spiegel magazine in a weekend interview that he would send the federal government a written request within the next two weeks to restore "orderly conditions" at the nation's borders.
Bavaria is the main entry point to Germany for refugees.
"I would advise us all to prepare a Plan B," Dobrindt said in an advanced release of an interview to run in the Muenchner Merkur's Tuesday edition.
Merkel has vowed to "measurably reduce" arrivals this year, but has refused to introduce a cap, saying it would be impossible to enforce without closing German borders.
Instead, she has tried to convince other European countries to take in quotas of refugees, pushed for reception centers to be built on Europe's external borders, and led an EU campaign to convince Turkey to keep refugees from entering the bloc. But progress has been slow.
Dobrindt rejected Merkel's argument that closing borders would jeopardize the European project.
"The sentence, the closure of the border would see Europe fail, is true in reverse. Not closing the border, just going on, would bring Europe to its knees," he said.
Source: http://www.reuters.com/article/us-europe-migrants-germany-idUSKCN0UW260