Angela Merkel’s conservative allies have lost their absolute majority in regional elections in the German state of Bavaria, according to exit polls.
The Christian Social Union (CSU) is set to suffer its worst result since 1950 with 35.5 per cent of the vote, down from 47.7 per cent five years ago.
Support for the centre-left Social Democrats (SPD), another coalistion partner, also slumped from 20.6 per cent to around 10 per cent, according to the exit polls by German broadcasters ARD and ZDF.
It leaves the Greens as the second largest party with 19 per cent and the anti-immigration Alternative for Germany (AfD) on course to enter the state legislature with 11 per cent.
If the polls are correct, the pro-immigration Greens could become a potential coalition partner for the CSU in Bavaria.
The CSU had been predicted to suffer heavy losses in the election, with analysts suggesting the result could pile further pressure on Chancellor Merkel, the leader of the Christian Democratic Union (CDU).
Before the vote in Bavaria, Merkel had urged her CSU and CDU allies to end their in-fighting.
Divisions between the two parties had widened further since an inconclusive national election forced them into a coalition with the SPD in March.
The CDU is also expected to lose votes in a regional election later this month in the western state of Hesse, home to the financial centre of Frankfurt.
Ms Merkel is then due to seek re-election as CDU party chairwoman in December.
The CSU, which has taken a hard line on immigration, has held an absolute majority in the Bavarian parliament for all but five of the past 56 years and has governed the prosperous southeastern state for 61 years.
Its leader, Interior Minister Horst Seehofer, has repeatedly clashed with Ms Merkel over immigration since 2015.
“This is a bitter day for the Christian Social Union,” CSU General Secretary Markus Blume said.
Bavarian premier Markus Soeder said that the CSU wanted to form a stable government as soon as possible. "Of course today is not an easy day for the CSU," he told a gathering of his party. "We did not achieve a good result. We accept the result with humility."
Additional reporting by Associated Press
