Merz poised for chancellery but coalition arithmetic remains uncertain

Germany goes to the polls on 23 February with the identity of the next chancellor all but settled. Friedrich Merz, leader of the Christian Democratic Union, heads a conservative alliance polling at roughly 30 percent, a lead wide enough to make his chancellery the baseline assumption in Berlin. What remains entirely open is the parliamentary arithmetic that will sustain him. The Alternative for Germany sits second at just over 20 percent, but every other party has ruled out governing with the far right. That exclusion removes the simplest path to a majority and forces the CDU and its Bavarian sister party, the CSU, into a negotiation whose shape will define the next legislative term.

The polling landscape and the AfD constraint

The Social Democratic Party trails at about 16 percent, the Greens at 13 percent. The liberal Free Democrats and The Left hover near the five percent threshold that determines parliamentary entry. If both clear it, the Bundestag will contain six parties, a fragmentation that makes two-party coalitions mathematically difficult and three-party arrangements more probable. The AfD's strength is not merely a numerical obstacle; it is a political one. Merz's declaration last week that he would advance parliamentary motions to restrict migration even if they passed only with AfD votes shattered the informal firewall that has kept the far right isolated since the party's rise. The move triggered a fierce pre-election debate about the boundaries of democratic cooperation and left the Greens, who consider Merz's border-closure plans illegal, declaring a coalition with the conservatives nearly impossible.

The Federal Statistical Office confirms that voter volatility has increased across the last three federal elections, with the combined vote share of the two traditional big-tent parties, CDU/CSU and SPD, falling from 56.8 percent in 2013 to 42.4 percent in 2021. That structural fragmentation is the backdrop to every coalition permutation now under discussion.

Grand coalition: the known quantity under new strain

A CDU/CSU, SPD grand coalition, or GroKo, is the most familiar configuration. Germany has been governed by one four times since 1949, three under Angela Merkel. The model offers arithmetic comfort: current polling suggests the two blocs would command a comfortable majority. But the personnel and policy context have shifted. Merz has moved the CDU notably rightwards on migration, internal security and fiscal discipline. The SPD, meanwhile, faces an internal reshuffle. Chancellor Olaf Scholz has already ruled out serving in a Merz cabinet. Defence Minister Boris Pistorius and party co-leader Lars Klingbeil, both centrists, are expected to lead SPD negotiations. Their willingness to compromise on migration, Merz's signature issue, will be the first test of whether a grand coalition can hold.

Merz himself acknowledged the difficulty this week. "It will not be easy after the election," he said, leaving open whether he would prefer the SPD or the Greens as partner. He then pointed to Boris Rhein, the CDU minister-president of Hesse, as a negotiator who had "impressively shown" how to manage such talks. After winning the 2023 Hesse state election, Rhein played the SPD and Greens against each other before choosing the SPD, judging them the more pliable partner. Merz has repeatedly cited Hesse as a blueprint for the federal level.

The Kiwi option and the migration fault line

Three of Germany's sixteen states, Baden-Württemberg, Hesse and Schleswig-Holstein, are currently governed by CDU, Green coalitions, nicknamed Kiwi after the parties' black and green colours. On paper, the overlap is substantial: both camps favour stronger defence spending, a firmer line on Russia and deeper support for Ukraine. But migration policy has become a chasm. Merz has pledged to close Germany's borders on his first day in office; the Greens regard such unilateral closures as violations of EU and international law. The rift widened when Merz accepted AfD votes for his parliamentary migration motions. Markus Söder, the CSU leader, has long ruled out a national coalition with the Greens, a veto that carries weight given the CSU's role as kingmaker within the conservative bloc.

The European Parliament has repeatedly stressed that member states must manage external borders in compliance with the Schengen Borders Code and the EU asylum acquis, a legal framework the Greens argue Merz's day-one closure would breach. Frontex, the EU border agency, coordinates operational support but has no authority to sanction unilateral border closures by member states.

Three-party arithmetic: Germany and Kenya coalitions

If the FDP and The Left both return to the Bundestag, a two-party majority for CDU/CSU plus either SPD or Greens becomes unlikely. That opens the door to tripartite alliances. A Germany coalition, black (CDU/CSU), red (SPD), yellow (FDP), would reunite the conservatives with their traditional liberal partners while adding the SPD as a stabilising centre. A Kenya coalition, black, red, green, mirrors the colours of the Kenyan flag and would bring the Greens into government for the first time at federal level alongside the conservatives. Both configurations are viewed with dread across the parties. The Scholz government's collapse in December, after three years of infighting between SPD, FDP and Greens, is a fresh warning. The fear is that ideological gaps on climate policy, fiscal rules and migration would paralyse a new three-way cabinet from day one.

The Hesse playbook and the leverage of the Greens

Merz's repeated invocation of Boris Rhein's Hesse negotiation is more than rhetorical. In 2023, Rhein used the Greens' desire for government to extract concessions from the SPD, then discarded the Greens once the SPD offered acceptable terms. At federal level, the Greens are expected to serve a similar leverage function: their presence at the negotiating table strengthens the conservatives' hand with the SPD, even if a Kiwi coalition is never the intended destination. This dynamic assumes the Greens enter talks in good faith, an assumption strained by the migration votes. The Greens' parliamentary leader, Katharina Dröge, has warned that Merz's firewall breach "destroys the basis of trust" for any coalition. Whether that is a negotiating position or a red line will become clear only after the ballots are counted.

SPD reshuffle: Pistorius and Klingbeil versus the left

The SPD's internal dynamics are a subplot with major consequences. Scholz's departure from the cabinet removes the architect of the traffic-light coalition but also the figure most associated with its failure. Pistorius, currently the most popular politician in Germany across party lines, brings a security-focused profile that aligns with Merz's emphasis on defence and border control. Klingbeil, as party co-leader, controls the organisational machinery. Both are pragmatists. The SPD left, clustered around the parliamentary group and the Juso youth wing, will resist concessions on migration and social spending. If Pistorius and Klingbeil cannot deliver a coalition agreement that satisfies the party base, the SPD could face a membership revolt, or a decision to go into opposition, which would force Merz into a three-party deal.