Roughly 85% of the UK's container volume growth in 2025 landed at one port complex — London — and the British Ports Association says that concentration is the strongest evidence yet against Brussels' carbon leakage claims. The BPA's new analysis, published this week, directly challenges the European Union's move to penalise UK container ports, arguing that infrastructure spending, not EU Emissions Trading System pricing, explains Britain's rising share of Northern European container activity.

The dispute has real commercial stakes. Earlier this year the EU proposed measures targeting UK container ports after Spain's EU ETS Observatory reported a sharp rise in the UK's share of Northern European shipping activity and branded it evidence of carbon leakage. If those measures advance, carriers calling at British terminals could face cost penalties, and shippers routing cargo through London, Southampton or Felixstowe could see landed costs rise relative to continental alternatives.

What does the BPA analysis actually show?

The analysis finds that the Observatory's figures do not reflect genuine changes in cargo volumes and instead overlook two structural factors: major port investments and shifts in global shipping networks. The most concrete of those investments is the £350 million berth that opened at London Gateway in late 2024 — a single facility that accounts for the overwhelming majority of the UK's subsequent volume growth.

New capacity, not diverted cargo, is the driver, the BPA argues. Around 85% of UK container volume growth in 2025 concentrated in London following the berth's opening, a distribution pattern that mirrors where capacity actually came online rather than where carbon-related cost advantages might apply.

The continental data undermines the leakage thesis further. Rotterdam, Antwerp-Bruges and Hamburg — the three hubs UK ports were allegedly poaching from — all recorded growth during the same period. Traffic rose on both sides of the North Sea simultaneously, which is difficult to reconcile with a narrative of cargo shifting from one side to the other to dodge emissions costs.

What are the stakes for carriers and shippers?

Mark Simmonds, Director of Policy and External Affairs at the British Ports Association, said British ports have invested hundreds of millions of pounds to attract more ships and handle more cargo, and that those investments are now delivering results through improved competitiveness. He described it as extraordinary that the EU might respond to that success by introducing penal measures against British ports.

Simmonds argued that all available evidence, including the EU's own assessments and data, shows UK throughput increases align with new port capacity coming online. For carriers, that reading matters: if the growth reflects added berth capacity at London Gateway rather than regulatory arbitrage, network decisions to add UK calls are commercially rational and should not attract punitive treatment. For shippers and forwarders, the analysis supports the case that UK routings remain competitively priced without hidden carbon-cost advantages that Brussels could later claw back.

Simmonds was careful to separate the competitiveness argument from climate policy itself. While expressing support for efforts to reduce shipping emissions, he stressed that climate policy must rest on sound evidence rather than assumptions that could damage competition and investment. That framing positions the BPA not against decarbonisation but against what it sees as a misdiagnosed enforcement response.

What happens next?

The EU's proposed measures remain on the table, and the BPA analysis now forms part of the UK industry's evidence base for pushing back. The outcome will hinge on whether Brussels accepts that a £350 million berth and an 85% concentration of growth in London explain the shifting share of Northern European traffic more convincingly than ETS price differentials do. With Rotterdam, Antwerp-Bruges and Hamburg all still growing, the data suggests continental ports have lost nothing — a point UK ports will keep pressing as the EU reviews its next steps.