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How legally binding is David Cameron’s renegotiation?

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The legal status of Cameron’s deal is complicated because it involves different systems of law – international law and EU law.

The majority of the deal takes the form of international law (for example the promise to exempt the UK from ‘ever closer union’ and the red card system for national parliaments) and this is binding on the countries that have agreed to it. To change it would require all the countries to unanimously agree – and the UK would clearly not consent to this. These parts cannot be challenged by the European Court of Justice (ECJ) as long as they do not conflict with current EU legislation. They will eventually be enacted as treaty changes requiring the ratification of the consenting parties.

Some parts of the deal, however, require a change in current EU law (such as the ’emergency brake’ on benefits, and laws on deporting EU migrants). This means that it is up to EU officials to make it happen because they are not bound by the agreement in the way that the member countries are.

Theoretically, because the deal was agreed by the member countries themselves, without the institutions as a party, it is not concretely binding on the ECJ or the European Parliament. It is conceptually possible for the ECJ to strike down the EU law parts of the agreement or for the parliament to amend it but this outcome is very unlikely for a number of reasons.

First, the court cannot strike down the deal of its own accord; it could only do so in response to a legal challenge from one of the member states.  Moreover, any legal challenge would be many years away. It is simply not possible for this to take occur in the immediate aftermath of the referendum, as has been claimed in some quarters.  All 28 member states have already agreed to the deal and so would be unlikely to mount such a challenge. Even if this happened, the fact that the deal was unanimously agreed by all the member states would be given huge weight by the EU court.

It remains to be seen what the reaction of the European Parliament will be. Those parts of the deal subject to the ordinary legislative procedure, such as the emergency brake on benefits, could be open to amendment by the Parliament. Again, the political pressure coming from the fact that member states have made a commitment to support the legislation would be difficult to ignore, but not impossible.

Taking all this into consideration, the simple answer is that overall the deal is legally binding in practice. The ECJ and European Parliament could theoretically challenge some of the deal, but in reality such a move would lack credibility and is therefore extremely unlikely.

It is worth noting, though, that because much of the deal will require changes to EU law and to the EU treaties, these elements could take a long time to come into effect. The last treaty, the Treaty of Lisbon (2009), took around 10 years to agree.


  • Tom Adamson-Green – EU Research Fellow 


If you would like to read more about this issue, take a look at this House of Commons Library Briefing Paper. 

Photo: Crown Copyright

Credit: Georgina Coupe