A compulsory purchase order shall, in so far as it authorises the compulsory purchase of land which is the property of a local authority, or has been acquired by statutory undertakers, not being a local authority, for the purposes of their undertaking or of land belonging to the National Trust for Scotland which is held by the Trust inalienably, be subject to special parliamentary procedure in any case where an objection has been duly made by the local authority or the statutory undertakers or the National Trust for Scotland, as the case may be, and has not been withdrawn.