- 32 A B - each of the two steps. This gives rise to two related issues. For each of the two steps: (1) what is the appropriate extent of judicial deference to be A B given to the executive’s decision; and (2) in light of the deference given, C D 57. E F C what is the judicial role, if any, in examining the executive’s decision. In respect of the first step, as in the present case, when the Chief Executive issues a certificate under NSL 47 certifying that an act involves national security when that question arises in the adjudication of D E F a case, that certificate is binding on the court. The court must fully accept G H the assessment in the certificate. That is deference in its absolute sense. If the assessment is made by the executive by some other means, as noted G H at [41] above, the court will give great deference to it as is commensurate I J with its highest importance. Similarly, in A, the majority of the House of Lords held that great weight was to be accorded by the court to the I J assessment by the UK Government that there was a public emergency K L threatening the life of the nation within the meaning of article 15 of the Convention because it was a judgment pre-eminently political in character K L entrusted to the executive and Parliament: see in particular, Lord Bingham M M at [29]. N N 58. O P In respect of the second step, in CCSU, the House of Lords held that because of deference, once the factual basis is established that national security is a factor relevant to the determination of a case, the court O P will accept the opinion of the executive on what is required to protect it, Q R unless no reasonable executive could have come to such a conclusion in the circumstances of the case; and that this is not abdication of judicial Q R duties but is an acknowledgement that the court is not in a position to S T substitute its opinion for the opinion of those responsible for national security: per Lord Fraser at p 402C; per Lord Scarman at pp 404E, 405E, 406B-G; per Lord Diplock at p 412F; and per Lord Roskill at p 420E. S T On U U V V