When the Advocate General says Westminster is sovereign and the Scottish parliament is not he is presuming a definition of sovereignty which is fundamentally foreign to the Scottish national constitution. More than this, he is assuming a unicity – a singular notion of sovereignty and power in a singular British state – that has never before been made explicit. He is giving England’s idea of sovereignty priority over that of Scotland. This engenders a worrying logical problem; unicity renders the heretofore existing duality of legal understandings impossible.
We will not get more powers with Brexit. Powers returning to the UK from the EU are matters of sovereignty; the very power that London is determined never to return to the Scottish people.