For years, federal politicians from all established parties have categorically ruled out any cooperation with the Alternative for Germany (AfD), erecting a so-called "firewall" (“Brandmauer”) against the party. Nevertheless, reports increasingly document instances where this firewall is eroding, with established parties cooperating with the AfD at the municipal level. Against this backdrop, our study analyzes the meetings of municipal councils at the district level in all eastern German states from mid-2019 to mid-2024. The analysis of 2,452 meetings, during which the AfD submitted a total of 2,348 proposals, reveals that content-related cooperation occurred in 484 cases. This corresponds to approximately 20.6% of the AfD’s proposals. In slightly more than half of these cases (244), at least five non-AfD representatives supported an AfD proposal or candidate. This represents roughly 10.2% of all proposals.

Significant regional variations are evident, but the areas with the strongest AfD presence are not necessarily those with the highest levels of cooperation. Content-wise, the AfD secures cooperation from established parties less often on controversial national topics, such as asylum or security, and more frequently on infrastructure-related tasks within the immediate jurisdiction of the respective councils, such as transportation issues. Overall, our study demonstrates that the contentious firewall, often assumed to have completely collapsed at the municipal level, has indeed developed cracks over the past five years but remains considerably more robust than widely believed. At the end of this paper, we discuss four conceivable strategic options for the future handling of the firewall.