The three major governing parties-CDU, CSU, and SPD-recorded a decline in membership over the past year. While the CDU’s earlier upward trend halted in 2025, the long‑standing downward trajectories of the CSU and SPD continued.
“CDU”
On 31 December 2025 the party had 356,769 members, a drop of about 2 % from the 364,202 recorded at the end of 2024 and from 363,101 at the end of 2023, according to the “Tagesspiegel” using CDU district data.
“CSU”
The CSU counted roughly 122,000 members on 31 December 2025, the party confirming this figure upon the newspaper’s request. That represents a loss of just under 3 % compared with 125,153 members at the end of 2024.
“SPD”
The SPD had 348,451 members as of 31 December 2025, again citing party district information from the “Tagesspiegel”. This is a decline of more than 2 % from the 357,116 members recorded a year earlier.
“Political context”
In February of the previous year the Bundestag was elected, leading to Friedrich Merz of the CDU’s election as Chancellor in May of a black‑red coalition. By 2024 the CDU had overtaken the SPD to become the party with the most members, a position it still held at the end of 2025.
