BREAKING NEWS: High Seas Treaty becomes UK law

The UK’s BBNJ Bill received Royal Assent today, becoming an Act of Parliament. This is the domestic legislation that enables the UK to ratify the High Seas Treaty.

It is a necessary step. It is not ratification.

Ratification is the formal process by which a country commits to be legally bound by an international treaty. Until that happens, the UK has no obligations under the agreement and no vote in how it is implemented.

The High Seas Treaty entered into force on 17 January after reaching the threshold of 60 ratifications last September. As of today, 85 nations have ratified, according to the High Seas Alliance. The EU and a majority of its member states are among them. So are China, France, Japan, and Brazil.

The UK has not.

Today’s Act clears the first hurdle. Secondary legislation still needs to pass before the UK can formally ratify. That means further regulations, including amendments to the marine licensing regime (the system governing who can do what at sea) to comply with the treaty’s environmental impact assessment obligations. The government has indicated it expects to complete this process over the summer, though no formal deadline has been published.

‘Work is already underway on the remaining steps to enable full UK participation as the treaty enters its implementation phase,’ said Seema Malhotra, Parliamentary Under-Secretary of State at the Foreign, Commonwealth and Development Office. ‘The UK helped negotiate this historic international agreement and was one of the first to sign it. We are now stepping up again to safeguard the ocean that underpins food security and livelihoods including here at home.’

The timeline is tight. COP1, the treaty’s first Conference of the Parties and its main decision-making body, is expected later this year. Once the UK deposits its instrument of ratification at the UN, the treaty enters into force for the UK 30 days later. If secondary legislation slips, the UK could arrive at COP1 without a vote.

To be clear: the UK would not be locked out. Non-parties can attend as observers. They can make statements. They cannot vote on the rules of procedure, budgets, or marine protected area proposals that will shape how the treaty actually works. For a country that claims to lead on ocean protection, observer status at the first meeting of a treaty it helped negotiate would be a poor look.

The UK signed the agreement on 20 September 2023, the day it opened for signature. Emma Hardy, Parliamentary Under-Secretary of State for Water and Flooding, announced at the UN Ocean Conference in June 2025 that enabling legislation would be introduced by the end of the year. The Bill was introduced in Parliament in September. Five months later, it received Royal Assent. In the same period, dozens of nations completed their entire ratification process.

The UK is not alone among major democracies in dragging its feet. The US and India have also not ratified. The UK has participated actively in the treaty’s preparatory commission sessions and contributed funding to support developing country engagement. The gap is not between the UK and indifference. It is between the UK’s rhetoric and its pace.

In January, 18 environmental organisations wrote to Foreign Secretary Yvette Cooper condemning the ‘glacial pace of government progress’ on ratification.

A word of caution. Royal Assent is not implementation. I have watched this play out before. The Animals (Low-Welfare Activities Abroad) Act received Royal Assent in September 2023. I was in the Lords when they debated it. Two and a half years later, the implementing regulations that would give it practical effect have still not been laid. The Act exists on the statute book. Without the implementing regulations, it has no practical effect. Next month I will be back in Westminster representing Whale and Dolphin Conservation, alongside Save the Asian Elephant, Born Free, World Animal Protection, and others, urging MPs to restart the conversation on implementation. Acts without secondary legislation are statements of intent, not enforceable law. The BBNJ Act faces the same risk.

What the treaty does

For readers unfamiliar with the BBNJ Agreement: roughly two-thirds of the ocean lies beyond any nation’s jurisdiction. Until now, there has been no comprehensive global mechanism to establish protected areas in these waters. Existing protections have been limited to specific regions or sectors.

The treaty changes that. It enables marine protected areas on the high seas. It requires environmental impact assessments for activities that could harm marine ecosystems in international waters. It establishes benefit-sharing frameworks for marine genetic resources, the biological material from deep-sea organisms with potential applications in medicine and biotechnology. It strengthens capacity-building and technology transfer for developing states.

What to watch

The secondary legislation timeline.

Without it, ratification cannot happen. The preparatory commission holds its third session from 23 March to 2 April 2026, where draft decisions on institutional design will be finalised ahead of COP1.

If the government delivers on its summer timeline, the UK ratifies in time and takes its seat as a party at COP1. If it does not, the country that signed on day one and claims to lead on ocean governance will be watching from the gallery while others set the rules.

Today’s Royal Assent is welcome. It is not enough, yet.