EU sort of bans Holocaust denial

Writes Dan Bilefsky in the International Herald Tribune:

The European Union approved legislation Thursday that would make denying the Holocaust punishable by jail sentences, but would also give countries across the 27-member bloc the option of not enforcing the law if such a prohibition did not exist in their own laws.

I'm troubled by the prospect that the European Union will legislate what can be said. To me this seems a text book example of a the sort of legislation the EU should leave up to member countries. A situation where no single entity can set the standards of acceptable speech in Europe is better for protecting free speech than a situation where the European Union takes that role.

I suppose this particular piece of legislation is tolerable as it need not be enforced, but the precedent is not good. Consider:

EU officials involved in the drafting of the law, which needed unanimous approval, said consensus had been achieved by allowing national laws to take precedence.

If the procedural bits of the European not-a-Constitution are eventually passed, wouldn't that mean that unanimity is no longer needed? If so, will the members which advocated for this legislation to take precedence over national laws have another go at it?

Beyond the general objection to the EU legislating in this area at all, I don't find this particular law very good. An official history with which it is illegal to disagree is a fundamentally bad idea, even in cases like the Holocaust where the events have been meticulously documented and the generally accepted version is beyond reasonable doubt. Letting politicians to decide on which topics people are not allowed to be wrong is to let them take aim at ideologies they oppose. Thus German anti-Nazi politicians want to ban the denial of Nazi crimes, Lithuanian anti-Communist politicians want to ban denial of Communist crimes, Armenian nationalists want to ban denial of the Armenian genocide, Turkish nationalists have banned calling the Armenian genocide by that name, and so on. Fighting against Nazism and Communism are noble causes in my opinion, but even then legislation codifying historical truths just isn't the right way to go about it.