The Advocate General of the ECJ has said that an EU law on harmonising telephone and internet data retention rules is an internal market, not a justice and home affairs issue, and therefore was correctly decided on by qualified majority vote back in February 2006. (see here too)
The Directive - seen as a response to the 7 July bombings in London - sets a time period of six months to two years during which telecom operators are to keep phone and internet data.
Ireland challenged the decision, arguing that it was made on the wrong legal basis, and should have been decided by unanimity, under the justice and home affairs provisions in the EC Treaty. The Advocate General opinion is not binding, but it does give an indication as to how the ECJ will rule in the end.
Regardless of the no doubt complicated details of the case, not only is this further evidence of the ECJ's 'power grab' but it is also an example of how QMV can be very problematic for member states - particularly the smaller ones like Ireland.
When talking about the Lisbon Treaty, its supporters - including the UK and Irish governments - have persistently dismissed arguments that it would lead to the loss of the veto in sensitive areas of policy, including justice and home affairs. We were constantly told that this wouldn't matter because votes are barely ever actually taken, with consensus being the normal way to reach decisions in the Council.
But now we see that actually, it does matter. The Irish government, which has been arguing so viciferously in favour of more QMV and a 50% loss in Ireland's power to block legislation it dislikes through the Lisbon Treaty, has behind the scenes been trying to get a JHA decision reversed because it wanted to be able to block it.
The ECJ will be pleased that it will no longer have to deal with such quibbles once Lisbon is in force - it will be quite clear in which areas (the vast majority) QMV will apply.
Don't say we didn't warn you.