(1)So much of any agreement relating to a tenancy to which this Part applies (whether contained in the instrument creating the tenancy or not) as purports directly or indirectly by any means whatsoever to preclude the tenant from making an application or request under this Part or provides for the termination or the surrender of the tenancy in the event of his making such an application or request or for the imposition of any penalty, restriction or disability on the tenant in that event, shall be void.
(2)Where—
(a)during the whole of the five years immediately preceding the date on which the tenant under a tenancy to which this Part applies is to quit the holding, premises being or comprised in the holding have been occupied for the purposes of a business carried on by the occupier or for those and other purposes; and
(b)if during those five years there was a change in the occupier of the premises, the person who was the occupier immediately after the change was the successor to the business carried on by the person who was the occupier immediately before the change;
any agreement (whether contained in the instrument creating the tenancy or not and whether made before or after the termination of that tenancy) which purports to exclude or reduce compensation under section 19 shall to that extent be void, so however that this subsection shall not affect any agreement as to the amount of any such compensation which is made after the right to compensation has accrued.
(3)In a case not falling within subsection (2) the right to compensation conferred by section 19 may be excluded or modified by agreement.