Bernd Prange’s €10,000 donation to Germany’s far-right party exposes growing tensions inside the Christian Democrats as a crucial eastern state election approaches.

A revolt by a longtime Christian Democratic politician in eastern Germany has opened an uncomfortable new front for Chancellor Friedrich Merz, testing whether his party can maintain its longstanding refusal to cooperate with the far-right Alternative for Germany as the AfD surges in the polls.

Bernd Prange, the Christian Democratic Union mayor of Altmärkische Höhe in Saxony-Anhalt and a member of the Stendal district council, has disclosed that he donated €10,000 to the AfD, announced that he intends to vote for the party in the September 6 state election and openly encouraged other conservative voters to do the same.

More provocatively for the CDU leadership, Prange said he hopes the AfD wins an outright majority in Saxony-Anhalt — not because he considers himself an AfD politician, he argues, but because such a result could force his own party to abandon the political “firewall,” or Brandmauer, that prohibits cooperation with the far right.

Prange has also called for Merz to be removed as CDU chairman, accusing the chancellor and his party leadership of surrendering the conservative identity of Germany’s traditional centre-right party. In an open letter made public this week, he complained that values including order, security, national sovereignty and economic restraint were increasingly absent from the CDU, while accusing the party of shifting to the left.

The intervention would ordinarily be a local party disciplinary matter. Instead, it has become politically significant because it comes just over two weeks before an election in which the AfD is positioned to achieve a historic victory.

A polling average published on August 12 placed the AfD at approximately 42 percent in Saxony-Anhalt, almost 20 percentage points ahead of the CDU at about 23 percent. Individual surveys have put the AfD as high as 43 percent. The party won 20.8 percent in the state’s previous election in 2021, while the CDU secured 37.1 percent, illustrating the extraordinary reversal in their political fortunes.

The AfD’s Saxony-Anhalt branch has been classified by the state’s domestic intelligence authorities as a confirmed right-wing extremist organisation. Yet its electoral strength has continued to increase, confronting Germany’s established parties with a growing strategic dilemma: how long can a party commanding more than 40 percent of the vote be isolated without making the formation of stable governments increasingly difficult?

That question now goes directly to the heart of Merz’s political strategy.

The chancellor has repeatedly insisted that the CDU will not cooperate with the AfD. At the CDU’s national conference in February, Merz argued that fundamental political differences separated the parties and said conservatives should actively confront, rather than accommodate, the AfD. In July, he again pointed to binding party resolutions ruling out cooperation with both the AfD and the Left.

The CDU’s formal position originates in a 2018 party resolution rejecting coalitions or comparable forms of cooperation with either party. The principle subsequently became known as the Brandmauer — a firewall designed to prevent the AfD from gaining political legitimacy or access to governing power through cooperation with mainstream conservatives.

But the electoral landscape of eastern Germany is making that firewall increasingly difficult to manage.

In states where the AfD approaches or exceeds 40 percent, excluding it from government can require the CDU to cooperate, formally or informally, with parties considerably further to its left. For some conservatives, this creates precisely the contradiction Prange has sought to highlight: the CDU refuses cooperation with the AfD while sometimes depending on parties such as the Social Democrats, Greens or the Left to build parliamentary majorities.

The issue has already produced visible disagreement inside the Christian Democrats. Saxony’s CDU Minister-President Michael Kretschmer said in July that politicians needed to speak with anyone willing to engage, declaring that those still discussing “firewalls” had failed to recognise the changed political environment. Merz responded by reiterating the CDU’s formal prohibition on cooperation with the AfD.

Prange has now pushed that internal argument much further.

The 59-year-old businessman, who has belonged to the CDU since 1992 and has served as mayor of Altmärkische Höhe since the municipality was established in 2010, transferred the money to the AfD in two instalments of €5,000. The AfD confirmed receiving both donations. Prange has said he intends his actions to provoke a confrontation with his own party and has indicated that he wants the CDU to expel him rather than resign voluntarily.

The reaction from the CDU has been swift but complicated by the approaching election. Saxony-Anhalt CDU Secretary-General Mario Karschunke described the matter as extremely serious and said party officials would consider expulsion proceedings. State premier Sven Schulze, who is leading the CDU campaign against the AfD, said he regarded Prange’s actions as wrong but indicated that disciplinary action would be addressed after the September 6 vote.

The controversy has also attracted attention from the CDU’s governing coalition partner. SPD leader Lars Klingbeil said the incident needed to be addressed seriously inside the Christian Democrats, although he added that he believed Merz when the chancellor said there would be no cooperation between the CDU and AfD.

For the AfD, meanwhile, the affair provides a powerful campaign narrative. A serving CDU mayor donating money to its campaign allows the party to portray the firewall not as a durable democratic consensus but as a strategy increasingly questioned even within Germany’s conservative establishment.

The stakes extend far beyond Saxony-Anhalt.

The AfD has also risen dramatically in national polling. Recent surveys have placed it at around 28 percent nationally, ahead of the CDU/CSU bloc in some polls. That growth has transformed what was once primarily a debate about containing a protest party into a fundamental question about the structure of Germany’s political system.

If the AfD eventually becomes the largest party across several eastern states, the CDU will repeatedly face the same choice: uphold the firewall and construct increasingly complex alliances with parties to its left, attempt minority governments dependent on shifting parliamentary support, or reconsider some form of engagement with the AfD.

For Merz, abandoning the firewall would carry enormous risks. It could fracture the CDU, undermine its claim to occupy Germany’s democratic centre-right and produce a political crisis within the federal coalition. Maintaining it, however, becomes progressively more difficult when parts of the conservative grassroots believe that the policy is helping the AfD rather than containing it.

Prange represents an extreme version of that frustration, and there is no evidence that his decision to finance and endorse the AfD represents the position of the CDU as a whole. Senior party leaders have explicitly rejected his actions.

Yet his rebellion matters because it gives a name and a face to a dispute that has been developing inside German conservatism for years.

The September 6 election in Saxony-Anhalt may therefore become more than a regional contest. A commanding AfD victory — particularly one approaching a parliamentary majority — could intensify pressure on CDU politicians to reassess how Germany’s centre-right responds to a rival that has moved from the political margins to become one of the country’s strongest electoral forces.

Merz has so far drawn his line clearly: no coalition and no political partnership with the AfD. The question now confronting the chancellor is whether he can persuade the rest of his increasingly anxious party to keep standing behind it.