It would be cowardly not to begin this week with comments on the reports that the UK government will opt out of the EU’s criminal justice measures. I stress at the outset that the views I give on this subject are mine, and not those of the organisation for which I work.

At root, the argument is over vision, not details. Talk about whether individual instruments, such as the European Arrest Warrant or the accumulating criminal procedural safeguards for defendants, are in the interests of the UK are not persuasive to Eurosceptics. That is because, at heart, the worldview of Eurosceptics does not include any scrap of belief that the UK’s interests are advanced by being hitched to Europe.

So why stick to Europe? I have two reasons, neither of them original: first, the nation state has brought hideous consequences in its wake (wars, statelessness, multiplicity of rules and tariffs for a start), and other models should be tried; and, second, the modern world, like it or not, is made up of large blocs where membership of such a bloc is probably more advantageous than remaining small and isolated (for instance, in economic clout to realise your wishes). To do as the UK government is apparently intending, and to opt out of the crime measures with the intention of opting back into those which it likes, is similar to the club member who attends the Christmas party only to collect his present, but won’t put his name down on the roster for helping with the preparations. Most people don’t like such behaviour, and it certainly has nothing to do with the ‘big society’.

But I really want to talk this week about the EU proposal to launch a European Public Prosecutor’s Office (EPPO), which will have an effect on all member states. Eurosceptics had better sit down and fortify themselves with a stiff drink right now. The idea has been around for several years, but has become more urgent through an addition introduced by the Lisbon Treaty (Article 86 of the TFEU) which allows for an EPPO ‘for investigating, prosecuting and bringing to judgment [...] the perpetrators of, and accomplices in, offences against the Union's financial interests’. Have another sip, Eurosceptics, because this is what Article 86 also says: ‘[The EPPO] shall exercise the functions of prosecutor in the competent courts of the member states in relation to such offences.’

There have been consultations, and there is another round about to take place. My organisation, the Council of Bars and Law Societies of Europe (CCBE), has in the past been against the idea, for instance because there would be an absence of parliamentary and democratic control, an inevitable future extension of activities of the EPPO into domestic matters, and likely forum shopping where there are dual offences. Another important point is that there is no obvious counterweight to the EPPO on the defence side: should there be a European Public Defenders Office as well?

To show how advanced matters are, there is even a project aimed at establishing a procedural framework for the EPPO. European Model Rules for the Procedure of the future EPPO have now been developed, following research carried out at the University of Luxemburg between 2010 and 2012, with financing from the European Commission and co-financed by the University of Luxemburg.

It might seem paradoxical to speak about such a controversial matter at the same time as defending the EU. But building something new is hard, and there are bound to be difficult discussions about the borders and competences of the new construction. I don’t want to turn up just to receive my Christmas present. I think we should also participate in the preparations.

Jonathan Goldsmith is secretary general of the Council of Bars and Law Societies of Europe, which represents around a million European lawyers through its member bars and law societies. He blogs weekly for the Gazette on European affairs