The hon. Gentleman is right, and I thank him for pointing me in that direction. Clearly, there would be substantial economic problems associated
with a border, but the fundamental problem would be the message that would be sent out to those who want to cause trouble, if there were to be a British presence on the border. That would be a step in the wrong direction in terms of a united Ireland and it could give such people a reason to resume the troubles. That is the major risk, which is probably why the Government and the European Union are both saying that progress is being made. No one wants to admit that this remains a problem without a solution, because of its potential to generate trouble.
I have referred in interventions to the port of Dover. Many Members will have visited it, as I have done, and I certainly recommend it. The first thing to know about the port of Dover is that it is not really a port. The port authorities clearly state that it is in fact a bridge. I have stood in the control tower and watched the trucks flowing virtually seamlessly—that is an interesting word; perhaps the Government could look at how things operate there—on to the ferries. They slow down and go into channels and if they are lucky they can drive straight on to the ferry while the trucks coming into the UK are being unloaded from the lower deck. There is nothing to stop those trucks getting on to those ferries. They are not booked on to a specific ferry; they just turn up and drive on to whichever one is there. The only checks that the UK is carrying out on trucks coming into this country are related to smuggling, and they are done on the basis of intelligence, rather than, for example, on the basis of checking one truck in every 100. That is why the system flows smoothly.