The hon. Lady is right. It raises huge questions about the rule of law, about the system would be enforced, and about how it could operate in a sensible and fair way without being opened up to challenge from other areas.
Crucially, the technology approach relies on cameras. I have no doubt that part of the response at Dover will be the introduction of new automated number plate recognition and other such mechanisms. As I said to the Prime Minister before Christmas, cameras are infrastructure. If we add a whole load of cameras to the Northern Ireland border, we will still be creating the infrastructure and—crucially—the targets that the police fear will become a focus for dissident groups who want to disrupt the peace process. That, I understand, is why everyone, including the Government, has concluded that cameras at the Northern Ireland border are not a sensible solution and should not be part of our approach.