21.—(1) Where any street is stopped up under article 17 (permanent stopping up, restriction of use of streets, public rights of way and private means of access), if National Grid has any apparatus in the street or accessed via that street National Grid has the same rights in respect of that apparatus as it enjoyed immediately before the stopping up and the promoter must grant to National Grid, or procure the granting to National Grid of, legal easements reasonably satisfactory to National Grid in respect of such apparatus and access to it prior to the stopping up of any such street, but nothing in this paragraph affects any right of the promoter or National Grid to require the removal of that apparatus under paragraph 24 or the power of the promoter, subject to compliance with this sub-paragraph, to carry out works under paragraph 26.
(2) Notwithstanding the temporary stopping up or diversion of any highway under the powers of article 16 (temporary stopping up and restriction of use of streets), National Grid is at liberty at all times to take all necessary access across any such stopped up highway and to execute and do all such works and things in, upon or under any such highway as may be reasonably necessary or desirable to enable it to maintain any apparatus which at the time of the stopping up or diversion was in that highway.