Greece, one of the world’s top maritime powers, is set to abstain from a key vote on a global carbon tax for shipping, signaling a retreat from earlier support for the International Maritime Organization’s (IMO) plan to make the sector pay for its carbon emissions.

Read also: Trump Administration Rejects Global Shipping Net-Zero Plan, Calls It “UN Tax on Americans”

According to a person familiar with the matter, Athens now intends to withhold its vote on the proposal, which aims to impose levies on maritime emissions exceeding one billion tons annually. The shift underscores growing unease within the world’s second-largest shipowning nation about the potential economic fallout of the measure.

Greece had previously voted in favor of a draft version of the framework in April, but the government has since cooled on the plan, questioning its feasibility and cost implications for global carriers. “Athens has always been skeptical of the net-zero framework and its impact on the shipping industry,” the source said. The Greek government declined to comment publicly.

The vote comes as geopolitical tensions deepen over maritime decarbonization. While the European Union is urging member states to support the carbon levy, the United States remains firmly opposed. Washington has warned that it could retaliate with tariffs, visa restrictions, and port levies if the IMO proceeds. It has also proposed adding another procedural step before the charge could take effect—effectively delaying its implementation.

Greece’s decision to abstain would mark a break from the EU’s unified stance on climate leadership. The European Commission last week described the IMO’s net-zero plan as a “significant milestone” toward decarbonizing global shipping and ensuring fair competition.

Greek officials have reportedly conveyed their reservations to EU authorities in writing, citing concerns over the availability and cost of cleaner marine fuels. “The framework depends on technologies that aren’t yet viable at scale,” the source said. “It penalizes companies that can’t access alternative fuels, driving up costs as shipowners compete for limited supplies.”

The outcome of this week’s IMO vote remains uncertain, especially amid U.S. resistance and divergent views among major maritime nations. In April, the draft plan received broad international backing, but industry concerns over cost, compliance, and competitiveness have since intensified.

Greece ranks as the world’s second-largest ship-owning nation—trailing only China—according to data from Clarkson Research Services. Its stance carries significant weight in shaping the direction of global maritime policy, particularly within Europe’s powerful shipping community.