The premiers of Hamburg, Bremen, Lower Saxony, Schleswig-Holstein and Mecklenburg-Vorpommern agreed the demand at a summit in Rostock on Thursday, arguing that ports have become critical national infrastructure for trade, energy and defence.   The push has gained fresh momentum from a new legal opinion commissioned by IHK Nord which concludes that substantially greater federal support can be provided without changing Germany’s constitution.   That challenges chancellor Friedrich Merz’s position at the National Maritime Conference in Emden, where he raised constitutional concerns over greater direct federal involvement in port funding.

Bremen mayor Andreas Bovenschulte said two separate legal studies now supported the case for increased federal contributions.   German ports estimate they face an infrastructure investment and maintenance backlog of around €15bn, covering ageing quays, terminals and other facilities as well as new requirements created by offshore wind, energy imports, digitalisation and military logistics.   The current €38m annual federal contribution is shared across all five coastal states and has remained virtually unchanged for more than 20 years.   Hamburg mayor Peter Tschentscher said the geopolitical shift meant ports now needed not only to be modernised but strengthened for dual-use military purposes and protected against sabotage.      The northern states also called for greater investment in port hinterland connections.