Opencast Coal Act 1958

17 (1) No compensation shall be payable under subsection (2) of section thirty-two of this Act for any year for which the interest of the owner of the relevant land is held subject to, and with the benefit of, a tenancy which was subsisting immediately before the operative date of the compulsory rights order in question, unless the rent payable under that tenancy for that year is a rent which is subject to a liability to be reduced in consequence of that order or of anything done in the exercise of rights conferred by that order, or is a rent which has been so reduced in pursuance of such a liability. E+W+S

(2) For the purposes of the preceding sub-paragraph the rent payable under a tenancy shall be taken to be subject to a liability to be reduced as therein mentioned if, under the terms and conditions of the tenancy or under any enactment applicable thereto, the tenant is entitled to require that rent to be so reduced, or is entitled to require the question whether the rent should be so reduced, or generally what rent should be payable under the tenancy, to be referred to arbitration or to any court or tribunal; and the reference in that sub-paragraph to a rent which has been so reduced in pursuance of such a liability shall be construed accordingly.