Christopher Howarth is a senior Political Analyst at the think tank Open Europe. Prior to Open Europe he worked as a Conservative Foreign Affairs Adviser and senior researcher to a Shadow Europe Minister.

On Monday, MPs will be asked to vote on whether to opt back into 35 EU crime and policing measures. This presents a difficult choice for MPs, because if the UK goes back into the measures it will have to do so under new terms under the power of the European Court of Justice (ECJ) for the first time.

In a nutshell, Conservative MPs are being asked to vote to hand over more power to the EU – or exit altogether a number of measures the Government believes are essential to fight crime. With an election around the corner, do MPs want to be accused by UKIP of siding with the EU against ancient UK liberties, or be presented by Labour as allowing criminals to escape justice due to an “obsession” with UK sovereignty. Not a happy choice?

So what does the electorate want MPs to do? A recent YouGov poll suggested that 56 per cent of Britons back the European Arrest Warrant (EAW), but when you look at the question that was asked no attempt was made to explain the actual choice involved – the fall back options or the question of the ECJ’s new jurisdiction.

On the other hand a poll for Open Europe found that 81 per cent of the British public want crime and policing dealt with at a national level. So the British people want UK rather than EU control over crime and policing, yet also want the EAW – are they mad?

Well, no – they are just displaying a level of common sense absent from those who negotiated the Lisbon Treaty. We can certainly cooperate with our EU neighbours, but there is no reason why cooperation should entail creating an EU criminal justice system with the ECJ sitting on top.

When Tony Blair negotiated the Lisbon Treaty, he realised that ceding control over criminal justice would make it difficult to avoid a referendum. He therefore brokered a deal: the ECJ got its new powers, and in return Blair got an opt-out. He did not want or seek to negotiate a deal that kept the UK in but without the Court. The opt-out allowed him to tell MPs there was no reason for a referendum – and he would then quietly opt back in later.

Opting-in will give the ECJ jurisdiction, but that is not the only problem. The EAW had a number of imperfections already. There are problems of extradition for petty crimes; extradition to await trial for long periods; extradition for crimes that are not crimes in the UK, and extradition to face unfair trials.

David Cameron himself was one of the first to raise these concerns as a backbencher, and went on to vote against the EAW. Some of these problems have been partially addressed by new UK law. They may work, but all the UK safeguards will now be subject to the ECJ – can we trust them?

The opt-out brokered by Tony Blair allowed for a five year delay which could have been an opportunity to renegotiate the whole area and the ECJ’s remit – perhaps by negotiating a UK EU bilateral agreement.  However, this opportunity was lost – probably due to Coalition politics. The Liberal Democrats, keen to fight for the civil liberties of those being extradited to the US, such as Garry McKinnon, are passionate about extraditing people to the EU. Europhillia trumps civil liberties

Even at this late stage, if it wanted, the Coalition could press for temporary EU legislation that could allow the relevant EU legislation under the block opt out (such as the European Arrest Warrant) to apply to the UK for a set period of time while a new bilateral treaty was negotiated.

A provision allowing this is there in the EU treaties, the Government (see par 2.10 of the European Scrutiny Committee’s report) has itself agreed that the EU has a “wide power” under the relevant Article 10 (4) of Protocol No 36 on Transitional Provisions attached to the EU treaties to adopt such necessary arrangements.”

However, the Government shows no sign of putting that option on the table, and will present the choice as one of two bad options. An opportunity to renegotiate has been lost.

So we are here because we are here. But, even without a transitional deal, it would not be the end of the world if we stayed out of the EA. There are fall back extradition procedures – the European Convention on extradition – and it is highly implausible that Italy would have hung onto Hussein Osman just to spite the UK (to shoot that canard). But in a trade-off between civil liberties and expediency the old systems were undoubtedly slower.

The British people are right to want to keep crime and policing at a national level. They are also right to want to cooperate with our neighbours as we do with states around the world. These two aims should not be irreconcilable.

Whatever the outcome of the vote on Monday, MPs should keep up the pressure to ensure that the whole area of EU crime and Policing law is included in the UK’s renegotiation package – the British people do not want to “let matters rest there.”

Firstly, there is no reason why the European Court of Justice should have jurisdiction. Such an approach would also fit with that other Conservative policy – to cut back on the judicial activism of the other European Human Right’s Court.

A renegotiated package should also make it clear that the UK is not going to allow itself to slide into an emerging EU criminal justice system. To date, we have seen the ECJ expanding its remit to police the EU’s free movement of people – making it harder to remove people from the UK. We now have the ECJ getting jurisdiction over the EAW to make it impossible to say no to an extradition – something even US states can do to each other in extremis.

The ECJ could then go one step further – arguing that since we have extradition without safeguards, we need harmonised standards of justice across the EU under the ECJ. So we could have harmonised EU justice with the ECJ as arbiter of who can and cannot come in and out of the UK. A EU criminal justice system in the making, and not one made with the intricacies of our common law system in mind. If we don’t want to go down that road – and the British people certainly do not – we need to draw a line somewhere.