9.11.2017 A & Ors v Secretary of State for the Home Department [2004] EWCA Civ 1123 (11 August 2004) 359. Indeed, given the conclusion that a person who was certified, but whose certificate has been revoked, should be treated as having the same right to appeal against his certificate as a person whose certificate is still in existence, it is not immediately easy to see why the latter person should enjoy the benefit of more potential grounds of appeal than the former person. Perhaps particularly if one brings ECHR into play on this issue, one might expect both categories of person to be entitled to raise the same grounds of appeal, unless that would give rise to real difficulties. The test to be adopted to establish whether there are "reasonable grounds" 360. The appellants criticise the approach adopted by SIAC to the evidence relied on by the Secretary of State in relation to each of the appellants on a number of grounds. Each of these grounds can, I think, be dealt with comparatively shortly, in light of the way in which s25 of the 2001 Act is worded. 361. The first criticism is directed towards the observation of SIAC that the test for certification under s21 of the 2001 Act is "not a demanding standard for the Secretary of State to meet", and its reference to "the low threshold of proof" that has to be established by the Secretary of State under s25(2)(a). 362. I can understand why those observations, if taken out of context, might be said to suggest an insufficient degree of care, or even a wrong approach, on the part of SIAC, when considering an appeal under s25. However, read in context, I am of the view that those expressions of opinion are not merely unexceptionable; they are right. 363. In the great majority of cases where the court has to arrive at its own view on an issue of fact or opinion, it normally must do so on one of two bases. In the criminal context, the court normally (but by no means always) has to be satisfied by the prosecution of the correctness of a particular fact or opinion beyond reasonable doubt; in a civil context, the party seeking to establish the fact or opinion almost always has to do so on the balance of probabilities. In the context of s25 of the 2001 Act, however, while SIAC has to make its own assessment of the evidence and arguments relating to the questions of whether an appellant is a risk to national security and a terrorist, the ultimate decision it is required to make is whether there are "reasonable grounds" for both "believ[ing]" that the appellant poses a threat to national security and "suspect[ing]" that he is a terrorist. 364. Those words are clear in their meaning, if not always easy to apply. The court is not infrequently called upon to determine whether a certain opinion is reasonable. It seems clear that, in such a case it is not the function of the court to form its own opinion, but to consider whether the opinion is one which a reasonable person could, in the relevant circumstances, hold. The wording of s25(2)(a) requires SIAC to carry out that type of exercise. It must simply inquire whether "reasonable grounds" exist for a particular belief and a particular suspicion. In order to be persuaded that "reasonable grounds" exist, SIAC does not have to be satisfied on the balance of probabilities either that the appellant is a threat to national security, or that he is a terrorist. 365. The appellants contend that such a literal reading of ss21(1) and 25(2) of the 2001 Act cannot be justified in light of the drastic consequences of upholding a s21 certificate, namely that the appellant can be detained in prison for an indefinite period (or at least until November 2006) even though he has not been charged, let alone convicted, of any crime. That argument is powerful if one concentrates solely on one of the unusual and important features of Part 4 of the 2001 Act, namely that it results in the deprivation of the liberty of an individual against his will in circumstances where that could not normally begin to be justified. 366. However, apart from the difficulty caused to the appellants' argument by the language of ss21(1) and 25(2) of the 2001 Act, it appears to me that their argument is also weakened by the other two unusual and important features of the 2001 Act. First, there is the threat to the realm perceived by the government and identified in the Schedule to the Derogation Order. Secondly, there is a factor, which perhaps only has substantial weight in this connection when linked to the threat to the realm: the difficulty faced by the executive in establishing that a person is a member of a terrorist network, particularly one such as Al-Qa'eda, and that he is a threat to national security, which involves contemplating future possibilities, rather than what is more familiar to the law, namely past acts. http://www.bailii.org/ew/cases/EWCA/Civ/2004/1123.html 84/113