(1)Where a person arrives at a place in the United Kingdom as a member of the crew of a ship or aircraft under an engagement requiring him to leave on that ship as a member of the crew, or to leave within seven days on that or another aircraft as a member of its crew, then unless either—
(a)there is in force a deportation order made against him; or
(b)he has at any time been refused leave to enter the United Kingdom and has not since then been given leave to enter or remain in the United Kingdom; or
(c)an immigration officer requires him to submit to examination in accordance with Schedule 2 to this Act;
he may without leave enter the United Kingdom at that place and remain until the departure of the ship or aircraft on which he is required by his engagement to leave.
(2)The Secretary of State may by order exempt any person or class of persons, either unconditionally or subject to such conditions as may be imposed by or under the order, from all or any of the provisions of this Act relating to those who are not patrial.
An order under this subsection, if made with respect to a class of persons, shall be made by statutory instrument, which shall be subject to annulment in pursuance of a resolution of either House of Parliament.
(3)The provisions of this Act relating to those who are not patrial shall not apply to any person so long as he is a member of a mission (within the meaning of the [1964 c. 81.] Diplomatic Privileges Act 1964), a person who is a member of the family and forms part of the household of such a member, or a person otherwise entitled to the like immunity from jurisdiction as is conferred by that Act on a diplomatic agent.
(4)The provisions of this Act relating to those who are not patrial, other than the provisions relating to deportation, shall also not apply to any person so long as either—
(a)he is subject, as a member of the home forces, to service law; or
(b)being a member of a Commonwealth force or of a force raised under the law of any associated state, colony, protectorate or protected state, is undergoing or about to undergo training in the United Kingdom with any body, contingent or detachment of the home forces; or
(c)he is serving or posted for service in the United Kingdom as a member of a visiting force or of any force raised as aforesaid or as a member of an international headquarters or defence organisation designated for the time being by an Order in Council under section 1 of the [1964 c. 5.] International Headquarters and Defence Organisations Act 1964.
(5)Where a person having a limited leave to enter or remain in the United Kingdom becomes entitled to an exemption under this section, that leave shall continue to apply after he ceases to be entitled to the exemption, unless it has by then expired; and a person is not to be regarded for purposes of this Act as having been settled in the United Kingdom and Islands at any time when he was entitled to an exemption under subsection (3) or (4)(b) or (c) above or, unless the order otherwise provides, under subsection (2) or to any corresponding exemption under the former immigration laws or under the immigration laws of any of the Islands.
(6)In this section " the home forces " means any of Her Majesty's forces other than a Commonwealth force or a force raised under the law of any associated state, colony, protectorate or protected state ; " Commonwealth force " means a force of any country to which provisions of the [1952 c. 67.] Visiting Forces Act 1952 apply without an Order in Council under section 1 of the Act; and " visiting force " means a body, contingent or detachment of the forces of a country to which any of those provisions apply, being a body, contingent or detachment for the time being present in the United Kingdom on the invitation of Her Majesty's Government in the United Kingdom.