Germany’s interior minister has offered to resign over Angela Merkel’s EU deal to tackle immigration.
Horst Seehofer heads the Christian Social Union (CSU), a key party in Mrs Merkel’s coalition. The two party leaders will hold crisis talks later.
Last week, Mr Seehofer threatened to turn asylum seekers away from Germany’s borders unless Mrs Merkel reached an acceptable deal with other EU partners.
His stance put Mrs Merkel’s coalition and her political future in question.
A compromise looks unlikely, the BBC’s Jenny Hill in Berlin reports.
On Sunday evening Mrs Merkel’s Christian Democratic Union (CDU) passed a resolution supporting her position on migration. CDU General Secretary Annegret Kramp-Karrenbauer said the party believed a European solution was necessary.
Then reports emerged from the CSU – the CDU’s Bavarian sister party – that Mr Seehofer had offered to resign both as party leader and interior minister.
Mr Seehofer complained during a meeting of top CSU officials that he had held a “conversation with no effect” with Mrs Merkel when they held talks on Saturday about the EU deal on migration, sources said.
Senior figures immediately tried to persuade Mr Seehofer not to step down, including CSU parliamentary group chief Alexander Dobrindt. “This is a decision that I just cannot accept,” Mr Dobrindt was quoted as saying.
In the early hours of Monday the party leader then announced he had agreed to hold final talks with the CDU as a “concession” in the interest of the country and the coalition.
Mrs Merkel had previously given a more upbeat account of Saturday’s meeting, telling broadcaster ZDF that she had made concessions to Mr Seehofer.
“The sum of all we’ve agreed is equivalent to what the CSU wants – that’s my personal view, but the CSU have to decide for themselves,” she said. She also expressed hope that the CDU and CSU could continue working together “because we are a success story for Germany”.
Both parties spent Sunday discussing the deal on immigration that Mrs Merkel fought hard to reach at last week’s European Union summit.
She said Greece and Spain had agreed to take back migrants stopped at the Bavarian-Austrian border who are proven to have entered their countries first – a move she hoped would allay Mr Seehofer’s concerns.
Some 14 EU states had agreed to take back migrants who reached Germany, according to a document circulated by the government in Berlin.
The divisions within the German government over the issue are also being played out in other EU countries, and three countries later said they were not part of the German deal: the Czech Republic, Hungary and Poland.
Correspondents say Mr Seehofer’s decision to confront Mrs Merkel over migration appeared linked to state elections in the autumn in which the CSU faces a challenge from the far-right anti-migrant Alternative for Germany (AfD) party.
However, opinion polls have suggested that Bavarians are more satisfied with Mrs Merkel than the CSU leader, weakening Mr Seehofer’s position.
Germany’s migrants: Seehofer offers to resign over migrants