Regulation 21 Exclusion and removal from the United Kingdom
(1)
A person is not entitled to be admitted to the United Kingdom by virtue of regulation 12 if his exclusion is justified on grounds of public policy, public security or public health.
(2)
A person is not entitled to be admitted to the United Kingdom by virtue of regulation 12(2) if, at the time of his arrival, he is not the family member of a qualified person.
(3)
A person may be removed from the United Kingdom—
(a)
if he is not, or has ceased to be—
(i)
a qualified person; or
(ii)
the family member of a qualified person;
(b)
if he is a qualified person or the family member of such a person, but the Secretary of State has decided that his removal is justified on the grounds of public policy, public security or public health.