I teach some constitutional law. There are several different conventions in play here. One is cabinet confidentiality, one is the confidentiality of legal advice received by the government, another is that a minister must not mislead parliament or the public. But these "rules" have exceptions, and since they are conventions they are not enforceable in the courts (Crossman diaries, anyone?). The courts may become involved if there is a breach of the Official Secrets Act, but since (I expect) Short's defence would be that she was defending law (or international law) rather than simply followng orders (Nuremberg trials) the government is likely to prefer to avoid the embarrasment of an OSA trial, although in legal theory there is no "public interest" defence to OSA charges.

Accordingly it's a matter of who's going to blink first, and that is going to be interesting.

If Short is right that the attorney general was told to change his advice about the legality of the Iran invasion because Bush told Blair so, then despite the fact that the decision to go to war is an exercise of the Royal prerogative by the PM on behalf of the crown, I incline to the view that the breach of cabinet confidentiality is the lesser of several evils. It cannot be a threat to our security forces, to talk about the fact of bugging, because all the "professionals" on every side knew that everyone bugged everyone.

I am however surprised that the inherent implication that Blair and pals would use the fruits of bugging to blackmail "friendly" powers has not caused more fuss. I think that's much more contentious than exposing the fact of the bugging.