Though several contentions appear to have been raised in the writ petition, the judgment of the Division Bench of the Calcutta High Court dated 12th February, 1987, (which is the one presently under appeal) records that "the only question which has been mooted and agitated before us is whether the impugned Act which provides for eviction of unauthorised occupants from public premises to the extent it has been extended to premises belonging or taken on lease by a corporation established by or under a Central Act and owned or controlled by the Central Government is ultra vires as it was beyond the legislative power of the Parliament to extend the applicability of the said Act to such premises." Though the appellants are interested only in denying the legislative power of Parliament in so far as it purports to extend the applicability of the 1971 Act to premises belonging to or taken on lease by what may be described as public sector corporations, the contention as urged is somewhat broader.