Justice and Home Affairs Opt-out

My point was not that we should not be party to the European arrest warrant; nor was it about the convenience of being in or out of it. It was about the method by which we are party to it. In other words, do we do it via a bilateral treaty which, as the hon. Gentleman rightly pointed out, we have with the United States, or should we opt in to justice and home affairs, which come under the jurisdiction of the European Court and can be changed under qualified majority voting without any say-so from the House?