F1SI 1985/454
23(1)The returning officer shall appoint and pay a presiding officer to attend at each polling station and such clerks as may be necessary for the purposes of the election, but he shall not appoint any person who has been employed by or on behalf of a candidate in or about the election.
(2)The returning officer may, if he thinks fit, preside at a polling station and the provisions of these rules relating to a presiding officer shall apply to a returning officer so presiding with the necessary modifications as to things to be done by the returning officer to the presiding officer or by the presiding officer to the returning officer.
(3)A presiding officer may do, by the clerks appointed to assist him, any act (including the asking of questions) which he is required or authorised by these rules to do at a polling station except order the arrest, exclusion or removal of any person from the polling station or refuse to deliver a ballot paper under paragraph (4) of rule 34 (including that paragraph as applied by rule 35, 36 or 37).