Candidate for Gelsenkirchen mayor from Germany's far-right Alternative for Germany (AfD) party Norbert Emmerich, and Enxhi Seli-Zacharias of AfD react to the exit polls for the North Rhine-Westphalian (NRW) local elections, in Gelsenkirchen, Germany, September 14, 2025. REUTERS/Leon Kuegeler/File Photo

By Petra Wischgoll and Thomas Escritt

COLOGNE (Reuters) -Germany's far-right Alternative for Germany (AfD) party made deep inroads in the country's most populous state in municipal elections on Sunday, reaching mayoral run-offs for the first time and underlining its appeal beyond its eastern heartland.

The conservative Christian Democrats (CDU) remained the strongest party overall but support for their national coalition partners the Social Democrats (SPD) declined in North Rhine-Westphalia (NRW), a western state of more than 18 million, while the AfD almost tripled its score from five years ago to 14.5%.

"There's no avoiding the AfD in NRW any longer," posted a jubilant party leader Alice Weidel.

FIRST TEST FOR THE COALITION

The vote was a first test for CDU Chancellor Friedrich Merz's uneasy coalition with the SPD which critics say is failing to tackle a sluggish economy and voter concerns about immigration.

Tackling migration is a priority for the AfD, which became Germany's second biggest party in February's federal election and was endorsed by tech billionaire Elon Musk.

Although the AfD's share of the vote was slightly lower than in February, its mayoral candidates progressed to second-round run-offs for the first time in three cities of the densely-populated Ruhr Valley, a former industrial heartland - Gelsenkirchen, Duisburg and Hagen.

SPD SEES SUPPORT SLIDE

Home to almost a quarter of Germany's 81 million inhabitants, the region's ethnically diverse mix of former mining regions, creative student cities, high-tech metropolises and sloping vineyards makes it an electoral bellwether.

Merz's conservatives polled 33.3% of the vote, down around one point compared to five years ago. The SPD slipped to 22.1% from 24.3%.

The losses are likely to heighten the pressure on Lars Klingbeil, Finance Minister and SPD leader, to boost the party's profile and assert himself as junior partner in Merz's coalition.

"WE CAN'T SLEEP EASY"

Soeren Link, the SPD mayor of Duisburg, who will face an AfD challenger in run-offs two weeks from now, blamed the party leadership for the debacle.

"Something is wrong with the strategy," he said, calling for the party to take a harder line on AfD signature themes like immigration. His town, once a steel-making powerhouse with a flourishing river port, is now one of Germany's poorest.

"This result should give us pause," said Hendrik Wuest, NRW's conservative state premier. "We can't sleep easy - not even my own party, which won the election so clearly."

Despite rising unemployment and economic uncertainty in Germany, the CDU's only slight decline in NRW could strengthen the case for the 50-year-old centrist Wuest to succeed Merz, 69, if he does not run again for chancellor in elections due in 2029.

(Reporting by Thomas EscrittAdditional reporting by Erol Dogrudogan; Editing by Alexandra Hudson)