Dan reminds me of the great words of Lord Hoffman, perfectly judged for circumstances such as these:

The Attorney General’s submissions and the judgment of the Special Immigration Appeals Commission treated a threat of serious physical damage and loss of life as necessarily involving a threat to the life of the nation. But in my opinion this shows a misunderstanding of what is meant by “threatening the life of the nation”. Of course the government has a duty to protect the lives and property of its citizens. But that is a duty which it owes all the time and which it must discharge without destroying our constitutional freedoms. There may be some nations too fragile or fissiparous to withstand a serious act of violence. But that is not the case in the United Kingdom. When Milton urged the government of his day not to censor the press even in time of civil war, he said: “Lords and Commons of England, consider what nation it is whereof ye are, and whereof ye are the governours”

This is a nation which has been tested in adversity, which has survived physical destruction and catastrophic loss of life. I do not underestimate the ability of fanatical groups of terrorists to kill and destroy, but they do not threaten the life of the nation. Whether we would survive Hitler hung in the balance, but there is no doubt that we shall survive Al-Qaeda. The Spanish people have not said that what happened in Madrid, hideous crime as it was, threatened the life of their nation. Their legendary pride would not allow it. Terrorist violence, serious as it is, does not threaten our institutions of government or our existence as a civil community.

For these reasons I think that the Special Immigration Appeals Commission made an error of law and that the appeal ought to be allowed. Others of your Lordships who are also in favour of allowing the appeal would do so, not because there is no emergency threatening the life of the nation, but on the ground that a power of detention confined to foreigners is irrational and discriminatory. I would prefer not to express a view on this point. I said that the power of detention is at present confined to foreigners and I would not like to give the impression that all that was necessary was to extend the power to United Kingdom citizens as well. In my opinion, such a power in any form is not compatible with our constitution. The real threat to the life of the nation, in the sense of a people living in accordance with its traditional laws and political values, comes not from terrorism but from laws such as these. That is the true measure of what terrorism may achieve. It is for Parliament to decide whether to give the terrorists such a victory.