Terrorism prevention and investigation measures bill

My hon. Friend has always taken a principled stand on these issues, and I respect him for it. Hon. Members on both sides of the House have recognised that in a tiny number of cases we will not be able to prosecute, because that would lead to disclosure and therefore, because it is based on intelligence, a risk to agents and techniques. I said in Committee that I wanted to see the figure reduced to the smallest irreducible number possible, because I accept that we are talking about special measures that are outwith the normal framework of our legal system and transparent justice. I therefore accept my hon. Friend's concern, but it is the case, I am afraid to say, that there are people who pose a significant and substantial threat to us who cannot be prosecuted at the current time, and some measures have to be taken to protect the public against them. None of us goes down this path with relish. I have said it before, but let me say to the hon. Member for Perth and North Perthshire (Pete Wishart), who intervened earlier, that this is not a matter of Labour Members rubbing their hands with glee and wanting to put people under house arrest. Rather, it is about saying, ““What is the absolute necessity to protect the public?””