http://www.legislation.gov.uk/ukpga/2001/24/section/21/2004-09-22Anti-terrorism, Crime and Security Act 2001An Act to amend the Terrorism Act 2000; to make further provision about terrorism and security; to provide for the freezing of assets; to make provision about immigration and asylum; to amend or extend the criminal law and powers for preventing crime and enforcing that law; to make provision about the control of pathogens and toxins; to provide for the retention of communications data; to provide for implementation of Title VI of the Treaty on European Union; and for connected purposes.texttext/xmlenStatute Law Database2024-05-222004-09-22 Part 4 211The Secretary of State may issue a certificate under this section in respect of a person if the Secretary of State reasonably—abelieves that the person’s presence in the United Kingdom is a risk to national security, andbsuspects that the person is a terrorist.2In subsection (1)(b) “terrorist” means a person who—ais or has been concerned in the commission, preparation or instigation of acts of international terrorism,bis a member of or belongs to an international terrorist group, orchas links with an international terrorist group.3A group is an international terrorist group for the purposes of subsection (2)(b) and (c) if—ait is subject to the control or influence of persons outside the United Kingdom, andbthe Secretary of State suspects that it is concerned in the commission, preparation or instigation of acts of international terrorism.4For the purposes of subsection (2)(c) a person has links with an international terrorist group only if he supports or assists it.5In this Part—“terrorism” has the meaning given by section 1 of the Terrorism Act 2000 (c. 11), and“suspected international terrorist” means a person certified under subsection (1).6Where the Secretary of State issues a certificate under subsection (1) he shall as soon as is reasonably practicable—atake reasonable steps to notify the person certified, andbsend a copy of the certificate to the Special Immigration Appeals Commission.7The Secretary of State may revoke a certificate issued under subsection (1).8A decision of the Secretary of State in connection with certification under this section may be questioned in legal proceedings only under section 25 or 26.9An action of the Secretary of State taken wholly or partly in reliance on a certificate under this section may be questioned in legal proceedings only by or in the course of proceedings under—asection 25 or 26, orbsecton 2 of the Special Immigration Appeals Commission Act 1997 (c. 68) (appeal).Ss. 21-23 continued in force in accordance with s. 29(2)(c) of this Act for a period of one year beginning with 14th March 2003 by S.I. 2003/691, art. 2Ss. 21-23 continued in force in accordance with s. 29(2)(c) of this Act for a period of one year beginning with 14th March 2004 by S.I. 2004/751, art. 2