I wish to take slight issue with the hon. Members for Perth and North Perthshire (Pete Wishart) and for Brighton, Pavilion (Caroline Lucas). The hon. Gentleman’s speech seemed to play to a particular event that will take place over the next few months in Scotland and the rest of the United Kingdom, and it was more about distancing the Scottish National party from the position taken by Labour. That is fair enough; he is entitled to do that but he seemed to be putting rather more heat than light into the debate. To be slightly more serious—as I am sure he intended to be—the problem with the approach taken by him and the hon. Member for Brighton, Pavilion is that they describe a black and white world where either we have the evidence, in which case we go through the court system, prosecute someone and if that is successful they receive an appropriate sentence, or else there is not enough evidence to bring forward a court case so someone is not controlled at all. The difficulty is that the world is not black and white in that way.
Suppose one of our intelligence agencies has information from a liaison partner—the United States, for example—about somebody’s connections, or plans that they may be involved in with a third party elsewhere in the world to commit an act of terrorism in this country. There is a problem with taking such a case through the courts because the information it is based on is governed by the control principle—namely that that information is the property of the other agency, which in this case is in the United States. To allow that information to appear in a court case as evidence would undermine the relationship between the UK and that liaison partner.