The Internet kill-switch: UK law

Communications Act 2003 and Civil Contingencies Act both give quite wide powers for the UK Culture Secretary (for it is that Hunt) to switch off the Internet to preserve "public order" - just as in most North African and Gulf states: "to protect the public from any threat to public safety or public health, or in the interests of national security". Department for Culture, Media and Sport explains: "It would have to be a very serious threat for these powers to be used, something like a major cyber attack. The powers are subject to review and if it was used inappropriately there could be an appeal to the competitions appeal tribunal. Any decision to use them would have to comply with public law and the Human Rights Act."
Note that these reviews take years and would not prevent the type of short-term switch-off seen recently in Libya and Egypt. It is in the end a matter of judgement and politics whether repression results from these laws.