Why not have a referendum on justice co-operation?

In the UK the Conservatives have been blundering about with EU policy again. Home Secretary Theresa May, who talked about rolling back the free movement of people not so long ago, is now talking up the possibility of the UK opting out of the area of freedom, justice and security altogether. The coalition LibDems have not exactly killed the idea, but pulled the rug from under May when he said that no decision had been made, leaving May to provide the House of Commons with an empty statement about the government's "current thinking".

There's a lot of comment about how short-sighted it is to pull out of justice co-operation, and on how the Conservative approach to the EU has been a shambolic case of issuing announcements with little thought and then scrambling to deal with the aftermath. While I agree that opting out of the JHA area en bloc is a terrible idea that would weaken the UK's security, I'm confused over why the Tories have been so inept over this issue: why not have a referendum on justice co-operation?

Seriously. If Nick Clegg will only go as far as saying that nothing has been agreed yet (suggesting that the LibDems might be reconciled to the opt-out if the UK opts back into several JHA measures), and ministers are going to engage in such policy kite-flying, then why not put the issue to the people or make noises about doing so? It would give the people a referendum on the EU, let people express an opinion on at least one aspect of the EU relationship that the Conservatives want re-balancing (and why not gauge opinion on what aspects of the EU the public want to buy into?), and would allow the Conservatives to partly deliver on their promise of a referendum on the Lisbon Treaty (in this case opting in or out of the post-Lisbon justice area).

The Home Secretary would not have been able to make a statement straight away, but the Conservatives could have started agitating for a referendum, and there is general agreement that some EU referendum has to happen sometime soon. It would have given the Conservatives space to test waters and refine their position and avoided statement grandstanding while winning a political point on the issue. Sounds like a better strategy than the current farcical posturing.

So why not have a referendum? Perhaps it's because it would be awkward for the party of law and order to campaign for opting out of law and order co-operation - maybe it's just simply politically uncomfortable as a gamble, with little likelihood of success. It's hard to sell the idea that the justice system won't suffer from the opt-out because we'll go back to the EU and negotiate specific opt-ins: not exactly a great rallying cry. And even a total opt-out with no subsequent opt-ins would be a hard sell.

In other words, if you hold a referendum on justice co-operation, the Europhiles would probably be the winners. Now that would be a Tory nightmare worse than their own bungling.