(1)If the Secretary of State is satisfied that any person—
(a)is or has been concerned in the commission, preparation or instigation of acts of terrorism to which this Part of this Act applies; or
(b)is attempting or may attempt to enter Great Britain with a view to being concerned in the commission, preparation or instigation of such acts of terrorism,
the Secretary of State may make an exclusion order against him.
(2)An exclusion order under this section is an order prohibiting a person from being in, or entering, Great Britain.
(3)In deciding whether to make an exclusion order under this section against a person who is ordinarily resident in Great Britain, the Secretary of State shall have regard to the question whether that person’s connection with any country or territory outside Great Britain is such as to make it appropriate that such an order should be made.
(4)An exclusion order shall not be made under this section against a person who is a British citizen and who—
(a)is at the time ordinarily resident in Great Britain and has then been ordinarily resident in Great Britain throughout the last three years; or
(b)is at the time subject to an order under section 6 below.