The UK Secretary of State for Exiting the European Union, David Davis, told parliament on 31 January that the UK will seek an alternative agreement with the International Atomic Energy Agency (IAEA) if it fails to negotiate "some sort of relationship" with the European Atomic Energy Community (Euratom) during Brexit negotiations. The government announced its intention to leave Euratom within explanatory notes to the bill authorising Brexit that it published on 26 January. The notes state the bill empowers the prime minister to leave both the European Union and Euratom.

The 1957 Euratom Treaty governs the peaceful use of nuclear energy within the EU. The Euratom Community is a separate legal entity from the EU, but it is governed by the bloc's institutions. Davis said today: "Euratom passes through to its constituent countries the regulations, rules and revision that it inherits, as it were, from the [IAEA], of which we are still a member. And when we come to negotiate with the European Union on this matter, if it's not possible to come to a conclusion, with some sort of relationship with Euratom, then we will no doubt be able to do one with the [IAEA], possibly the most respectable international body in the world."

He added: "Our aims are clear: we will maintain the closest possible nuclear cooperation with the European Union. That relationship could take a number of different forms and will be of course subject to negotiation, which will start after we have notified them" of the UK's intention to trigger Article 50 to exit the EU.

If the UK ceases to be part of Euratom, then it is vital that the UK government and its partners in the EU agree transitional arrangements to give time to negotiate and complete new agreements with other EU member states, Foratom, the Brussels-based nuclear industry trade body said on 30 January. Foratom said the UK would also need to negotiate and complete new agreements with countries including the US, Japan and Canada who have nuclear cooperation agreements within the Euratom framework. Foratom said the UK should remain a member of Euratom until these arrangements are put in place, adding that it supports the position of its UK member, the Nuclear Industry Association, that the European nuclear industry’s preferred position is to maintain the UK’s membership of Euratom.