Yes, it is typically British, which makes me wonder why you are looking for a cite for it. Seriously, you want a cite? OK, try this; apart from the UK itself, every single Commonwealth realm that now exists, and therefore the separate crown of each Commonwealth realm, was created by or under an Act of the Westminster Parliament, and the British monarch of the day would never have become monarch of those realms if the Westminster Parliament had not so arranged it. There is no case in which the British monarch has accepted the crown of another commonwealth realm without the advice and assent of her UK advisers. And since her doing so affects the foreign relations of the UK (e.g. the UK cannot exchange ambassadors with another commonwealth realm) this is entirely proper and there is no reason for it to change.
But Austria is a party to the Convention on Nationality; the ECJ judgment explicitly points that out. The UK is not. Nothing in what the ECJ says suggests that they think the Convention is binding on states that aren’t party to it.
In any event, I don’t think Rottman says what you think it says. Rottman was an Austrian citizen by birth. He applied for, and was granted, naturalisation as a citizen of Germany, which under Austrian law meant that his Austrian citizenship was terminated. Subsequently it had emerged that he had lied in his application for German citizenship; when this emerged, his German naturalisation was revoked, leaving him apparently stateless. He brought proceedings in Germany seeking to annul the revocation of his German nationality, on the grounds that it would leave him stateless. (He did not seek the revival of his Austrian citizenship; the whole point of his naturalisation in Germany was to avoid extradition to Austria, where he was wanted for fraud, and being an Austrian citizen was not helpful to him in that regard.)
The German court referred two questions to the ECJ:
-
Is it permitted for Germany to withdraw Rottman’s citizenship if that will leave him stateless, or with no citizenship in any EU member state?
-
If Germany withdraws Rottman’s citizenship, is Austria bound to revive his original citizenship, so that he retains EU citizenship?
The ECJ answered the first question with “yes”. In the circumstances, Germany could revoke Rottman’s naturalisation.
But the ECJ declined to answer the second question. Rottman had not sought to have his Austrian citizenship revived, and the Austrian government had not taken any decision about that, and there was therefore no decision to challenge. “The Court cannot . . . rule on the question of whether a decision not yet adopted is contrary to European Union law”. If the question came before the Austrian authorities, they would have to make a decision about it “in light of the principles referred to this judgment” (basically, the principal of proportionality). The court does not say that, if the decision comes before the Austrian authorities, they have to restore Rottman’s Austrian citizenship.
And my point is that nothing in British nationality law or practice supports your claim in this regard. Time and again British citizens who have not voluntarily claimed another citizenship have had their British citizenship withdrawn. It’s what normally happens when a new Commonwealth realm, and associated new citizenship, comes into being; it’s what the framework of Commonwealth citizenship envisages. That doesn’t mean it has to happen if and when Scotland becomes independent; an exception for Scotland might be negotiated, and I think within the context of shared EU membership it probably will be. But it puts the kibosh completely on any claim that the Scots have a right for it not to happen.