If we're bound, presumably there's nothing stopping us unbinding ourselves, Rickster. We're bound only for so long as we agree to be bound.
The EU and the ECHR appear to be separate things anyway (re fat buddha's point). We will still be bound by the ECHR if we left the EU, and we can presumably opt out of whatever we want in the ECHR (or the whole thing) without leaving the EU.
The discussion in this thread is academic anyway. The government won't give the people the death penalty in any case.
Edited: 15/02/2013 at 17:03