(1)The powers conferred by subsections (7) to (10) of section 5 above shall be exercisable, with the consent of the appropriate authority, in relation to land in which there is a Crown interest or a Duchy interes,t but in which there is also an interest held otherwise than by or on behalf of the Crown.
(2)In subsection (1) above " Crown interest " means any interest belonging to Her Majesty in right of the Crown, or belonging to a government department, or held in trust for Her Majesty for the purposes of a government department; " Duchy interest " means an interest belonging to Her Majesty in right of the Duchy of Lancaster, or belonging to the Duchy of Cornwall ; and for the purposes of that subsection " the appropriate authority",in relation to any land—
(a)in the case of land belonging to Her Majesty in right of the Crown and forming part of the Crown Estate, means the Crown Estate Commissioners, and, in relation to any other land belonging to Her Majesty in right of the Crown, means the government department having the management of that land ;
(b)in relation to land belonging to Her Majesty in right of the Duchy of Lancaster, means the Chancellor of the Duchy ;
(c)in relation to land belonging to the Duchy of Cornwall, means such person as the Duke of Cornwall, or the possessor for the time being of the Duchy of Cornwall, appoints ;
(d)in the case of land belonging to a government department or held in trust for Her Majesty for the purposes of a government department, means that department ;
and, if any question arises as to what authority is the appropriate authority in relation to any land, that question shall be referred to the Treasury, whose decision shall be final.