(1)Arrangements may be made between any department of the Government of the United Kingdom and any Northern Ireland department for any functions of one of them to be discharged by, or by officers of, the other.
(2)No such arrangements shall affect the responsibility of the department on whose behalf any functions are discharged.
(3)In this section references to a department of the Government of the United Kingdom include references to any Minister of the Crown and references to a Northern Ireland department include references to the head of a Northern Ireland department; and this section shall have effect in relation to the Post Office as it has effect in relation to a department of the Government of the United Kingdom.