The Greater London Authority (Referendum Arrangements) Order 1998

9.  For the purposes of paragraph (3) of rule 34 (tendered ballot papers), the same list may be used for the poll at the referendum and the poll at the ordinary election and, where it is so used, an entry in that list shall be taken to mean that tendered ballot papers were marked in respect of each poll, unless the list identifies the poll at which the tendered ballot paper was marked.