My Lords, I think it is the occasion for the Labour Benches. I remind the House that the Supreme Court gave us the benefit of its wisdom on constitutional matters in the case of Gina Miller, which we have heard about. In that case, the Supreme Court’s principal conclusion was that primary legislation is required to authorise the UK’s withdrawal from the European Union. I make it clear that this Bill is a notification Bill; it is not an authorisation Bill. It does not authorise withdrawal from the European Union. What it does is to notify other European Union members that we are in a process of negotiation. The withdrawal must come back before this Parliament.
I also remind the House what the Supreme Court judges said. They said that the reason why this was a matter for Parliament—both the notification and, finally, withdrawal—was because any fundamental change to our laws that inevitably amends or abrogates our individual rights requires the approval of Parliament. That is one of the essential constitutional principles under which our system operates: that anything involving our rights—whether they are to trade with, to live in or to travel to the European Union—we have introduced into domestic law. Because that therefore involves the rights of citizens, Parliament is the place that has to make the decision and approve any changes to that law.
The concern that I raised in Committee late at night, when most people were no longer here, was that I had heard repeatedly from Ministers that if there was not a deal, or if Parliament decided that the deal was not good enough, we would walk away and that there was therefore authorisation from the people, having taken part in the referendum, to walk away. That flies in the face of what was said by the constitutional court of this country—the Supreme Court, which deals with constitutional issues—because walking away and embarking on an engagement in trade worldwide under the WTO rules also involves an amendment or abrogation of some of the rights that citizens in this country have. It has implications. That is why it is a constitutional matter and why this House has a particular role to play.