BERLIN — German Chancellor Friedrich Merz ruled out working with the Alternative for Germany (AfD) party following a debate within his Christian Democratic Union about possible future cooperation with the rising far-right force.

“This party [the AfD] has declared its intention to destroy the CDU,” Merz, who is also the CDU’s leader, told reporters in Berlin on Monday. “We accept this challenge. We will now make very clear where the AfD stands in terms of content. We will distance ourselves very clearly and distinctly from them. And above all, it is important that we counter this with successful government work.”

Merz’s conservatives have long struggled to find the right approach to the AfD, which has seen its support soar since the country’s February election. Merz, in the immediate run-up to that vote, tried to push a controversial immigration bill backed by the far right through the German parliament. That move drew heavy criticism, including from within his own ranks.

Back then, Merz defended his approach, but pledged to uphold the firewall in German politics that was set up to prevent cooperation with the far right. But as the AfD keeps gaining traction, members of Merz’s conservatives — especially from eastern German states — have argued that the firewall is no longer sufficient to stop the rise of the far right.

The AfD is now the largest opposition party in the Bundestag. The far-right party has found success by depicting itself as the only truly anti-immigration force in Germany, mixed with an anti-war rhetoric that is skeptical of Germany’s ongoing support for Ukraine and Berlin’s efforts to turn the Bundeswehr into Europe’s strongest army.

Merz’s comments come as a discussion unfolded last week within his center-right party about its handling of the AfD in advance of a series of state elections next year, including two in eastern German states where the AfD is polling around 40 percent, far ahead of all other parties.

“We want and can win all of these elections, and we can remain the strongest political force in Germany,” Merz said following a seven-and-a-half-hour-long meeting with party leadership on Sunday that was focused on developing a strategy for the upcoming election year.

The secretary-general of the CDU, Carsten Linnemann, presented a three-pronged approach to combat the AfD.

Firstly, the CDU’s presence is to be strengthened in the two eastern German states where the AfD is leading in the polls, to counter the dominance of the party at the local level. Secondly, expert committees are to be set up to develop ideas to shape the political agenda, which in turn should lead to the third goal, namely to create a positive image of the CDU as a party that seeks solutions, in contrast to the AfD, which focuses on problems.

Rethinking the firewall

Germany’s mainstream political forces have had a Brandmauer, or firewall, in place since the end of World War II to prevent cooperation with far-right parties.

Merz’s plan earlier this year to accept AfD support to pass an immigration bill was part of a preelection effort to win back voters who had defected to the far right. The tactic drew heavy criticism from Merz’s left-leaning rivals, who accused him of breaking Germany’s postwar quarantine of the far right and forgetting the lessons of the country’s history.

As chancellor, Merz pointed to the need to clearly distinguish his conservatives from the AfD.

“The public perception is increasingly solidifying that we could achieve a great deal together if we only wanted to. No, ladies and gentlemen, that is not the case,” he said Monday. “The AfD is questioning the fundamental decisions made by the Federal Republic of Germany since 1949. It is questioning all the fundamental decisions that we too have helped to shape. And that is why the hand that the AfD keeps reaching out is, in reality, a hand that wants to destroy us.”

However, he added, “Neither the secretary-general nor I used the word firewall. That is not the way we speak.”