So the big Cameron speech on Europe has come and gone. He devoted precisely 12 words in it to the most pressing EU issue which will arise before his beloved referendum even takes place: that of the opportunity for opt-out by the UK government from the EU crime and policing laws that were entered into before the Lisbon Treaty. He boasted that his government was ‘launching a process to return some existing justice and home affairs powers’. My question is whether a lawyer’s response to this specific opt-out question is possible.

Protocol 36 to the Lisbon Treaty gives the UK the right to opt out en bloc of all the police and criminal justice measures adopted under the Treaty of Maastricht ahead of June 2014, when the Court of Justice of the EU will acquire jurisdiction over them. It is often overlooked that this opt-out excludes many important measures, such as the minimum procedural safeguards for suspects and defendants, which the UK has expressly opted in to after Lisbon. There are around 130 pre-Lisbon measures, but all parties seem to agree that the European Arrest Warrant is the most significant of them. Even pro-opt-out bodies suggest that the UK should opt back into the Arrest Warrant after modest reform. So why the fuss?

Thinktanks and research institutes – packed with genius lawyers – come to opposite conclusions on the question. Here is the view of the University of Cambrige’s Centre for European Legal Studies: ‘If the opt-out were exercised, practical considerations would force the UK to seek to opt back into many of them – and the ones from which the UK could safely remove itself permanently are ones which impose no practical constraints on the UK, from which a UK opt-out would serve no practical purpose.’ Here is the opposite view from Open Europe: ‘The UK should exercise its block opt-out regarding EU crime and policing laws which entered into force before the Lisbon Treaty … while some of the EU crime and policing measures have proved valuable, many instruments are flawed or of minimal operational relevance to the UK.’

I can see that English lawyers might have a professional response to harmonisation of civil law – for instance, the European contract law initiative which is slowly making its way through the EU institutions. At present, lawyers in England and Wales benefit economically from the lack of a harmonised EU contract law. Given the dominance of UK firms and of Anglo-Saxon procedures in international transactions, the contract law of England and Wales is used more frequently than it would otherwise be if there were a European contract law (although the UK never puts it in those naked terms). But criminal law? It is not a subject where English law is able to put forward a similar argument.

Consequently proponents of opt-out talk about democracy and national control. These are arguments not about the legal measures themselves, but about the UK’s membership of the EU as a whole. That is a debate for the promised referendum and would take a volume to deal with. Nevertheless, I cannot resist saying that I would put more faith in the argument about democracy if those who advance it had actually done something about the biggest recent threat to UK democracy – the Murdoch state-within-a-state saga (‘this is a load of codswallop cooked up by the Labour Party’ – Boris Johnson; Rupert Murdoch is ‘one of the most impressive and significant figures of the last 50 years’ – Michael Gove). And as for national control, this relates to whether the current size and shape of the UK is some mystical perfect whole, pre-ordained for all time and not to be meddled with, when we know from current affairs (the forthcoming Scottish vote for independence) or the distant past (when swathes of France belonged to England), let alone the British Empire, that there is no pre-ordained mystical perfection to the size of any polity.

I think we need to separate the legal arguments about the benefits and disadvantages of opt-out, which is a limited and rather technical argument relating to a fixed set of measures, from the identity crisis which we are suffering as a result of post-imperial trauma and the 20th-century rise of the US. We can keep the identity crisis for the forthcoming EU referendum (for which a good map, and our trading statistics, are the indispensable tools).

For the opt-out, once you extract the identity crisis arguments from the debate, the consensus seems to be that a lot of good and no great harm is done by staying in the crime measures. It might be tempting to touch the sore spot of our identity crisis and say ‘opt-out!’, but we should remain rational and calm as lawyers.

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