As the IMO prepares to decide shipping’s most consequential climate measure in decades, a rare show of unity from leading shipowner associations faces opposition from the likes of John Fredriksen, Greek giants, leading class societies and Washington.

With days to go before the International Maritime Organization’s (IMO) extraordinary session on the Net Zero Framework (NZF), a deep rift has emerged across the shipping industry.

Seven leading shipowner associations – from Japan, Norway, Denmark, the UK, Belgium, The Netherlands and Singapore – have just issued a joint appeal urging governments to “make history in London” by approving the global decarbonisation plan — even as powerful opposition gathers from some of the sector’s most influential players.

“The adoption of the Net-Zero Framework would be a major milestone for global climate regulation,” the associations declared in a joint statement released this week. “Anything else would be a major setback for the green transition and risk leaving the industry with a complicated patchwork of regional climate regulations.”

The statement argues that the IMO’s framework — years in the making — is essential to provide predictability for investors and to scale up production of alternative fuels.

“Our industry, which by its very nature is global, absolutely needs a global regulation – also to address climate change,” said the signatories.

“The alternative is a complicated and inefficient patchwork of national and regional regulatory frameworks that would derail the energy transition and jeopardise world trade through distorted market conditions and unfair competition.”

The framework, due for a final vote next week, would set a global carbon levy and fuel standard aimed at achieving net-zero emissions by 2050. It would also establish a central Net Zero Fund to reward compliance and finance green infrastructure.

While backing the framework’s ambition, global tanker organisation INTERTANKO this week called for a more measured approach to implementation.

“The framework will create certainty, allowing shipowners and operators to focus on operational feasibility without the burden of regional unpredictability,” said Emma Scheiris, INTERTANKO’s deputy director for environment.

Scheiris warned, however, that the debate had become “polarised” and that the IMO must ensure “all transitional pathways remain in place for the long-term shift to zero- and near-zero fuels.”

She listed several unresolved technical hurdles: the absence of a global sustainable fuels certification scheme, the need for sound life cycle assessment (LCA) methodologies, and clear crediting for non-fuel energy sources such as wind propulsion.

“While maintaining the Polluter Pays principle, we need to provide the required investment security to unlock capital for a decarbonised future,” Scheiris said. “Beyond compliance, this is about establishing a framework that enables the maritime industry to accelerate toward zero-GHG shipping.”

But not everyone is onboard. A powerful bloc of major shipowners — including John Fredriksen’s Frontline, George Economou’s TMS Group, Evangelos Marinakis’s Capital Maritime, the Angelicoussis Group, and Saudi state carrier Bahri — has come out against the deal in its current form, warning it could “impose excessive financial burdens on the industry and consumers.”

The opposition, coordinated during London International Shipping Week last month, also includes Dynacom, GasLog, Seapeak, and Stolt Tankers. Together, they represent a significant share of the global tanker and gas carrier fleet.

“As it stands, we do not believe the IMO NZF will serve effectively in support of decarbonising the maritime industry nor ensure a level playing field as intended,” the group stated, calling for “critical amendments” before adoption.

Greek shipping minister Vassilis Kikilias echoed their concerns, telling IMO secretary-general Arsenio Dominguez in London that “changes are essential” before the framework can be accepted.

Dominguez, however, struck a confident tone at the same event. “I remain convinced the framework will be adopted,” he told delegates. “I base that on the track record of the organisation, on the co-operation that we all have, and the understanding that we still have some challenges and concerns.”

The IMO rarely resorts to formal voting, but sources in London say a ballot looks increasingly likely. If consensus cannot be reached, adoption will require a two-thirds majority — 108 of the 176 member states that have ratified MARPOL Annex VI.

The Getting to Zero Coalition, representing more than 180 companies and several of the world’s largest shipowners, last month issued a statement calling on member states to adopt the framework without delay.

“Prolonged uncertainty could put very large investments — ones that will be critical for the future of global trade — at risk,” the coalition said. “The absence of global regulatory guidance will raise the costs of change in the long run — costs that the industry, countries, and consumers will bear.”

Patrick Verhoeven, managing director of the International Association of Ports and Harbors (IAPH), also urged IMO members to seize the moment.

“A failure to adopt the framework would create absolute investment uncertainty,” Verhoeven warned. “Achieving IMO’s net zero targets would become impossible.”

Adding to the tension, the US remains firmly opposed to the framework. Washington walked out of April’s MEPC session and has since warned that countries supporting the deal could face retaliatory measures ranging from tariffs to port levies and visa restrictions.

Analysts say the vote could hinge on a small number of undecided states — including several from Southeast Asia, the Middle East, and Latin America — where political and economic alignments are in flux.

Splash will be bringing readers details of all the key outcomes from the IMO meet-up next week.