(1)For the purpose of filling a casual vacancy in the membership of the Assembly, the date on which a vacancy is to be regarded as occurring shall be—
(a)in the case of any person being returned—
(i)at an ordinary election, as the Mayor and also as the Assembly member for an Assembly constituency, or
(ii)at an election under section 16 below to fill a vacancy in the office of Mayor when he is an Assembly member,
on the date on which he is returned as the Mayor or, as the case may be, to fill the vacancy in that office;
(b)in the case of any person being returned as mentioned in section 16(10) below, on the date on which he is returned to fill the vacancy in the Assembly constituency;
(c)in the case of non-acceptance of office by any person who is required to make and deliver a declaration of acceptance of office, on the expiration of the period appointed under this Part of this Act for the delivery of the declaration;
(d)in the case of resignation, upon the receipt of the notice of resignation by the proper officer of the Authority;
(e)in the case of death, on the date of death;
(f)in the case of disqualification under the [1998 c. 18.] Audit Commission Act 1998 or by virtue of a conviction—
(i)on the expiration of the ordinary period allowed for making an appeal or application with respect to the relevant order or decision under that Act or (as the case may be) that conviction, or
(ii)if an appeal or application is made, on the date on which that appeal or application is finally disposed of or abandoned or fails by reason of its non-prosecution;
(g)in the case of an election being declared void on an election petition, on the date of the report or certificate of the election court;
(h)in the case of a person—
(i)ceasing to be qualified to be an Assembly member, or becoming disqualified, for any reason other than one mentioned in paragraphs (a) to (g) above, or
(ii)ceasing to be an Assembly member by reason of failure to attend meetings,
on the date on which his office is declared to have been vacated either by the High Court or by the proper officer of the Authority as the case may be.
(2)The proper officer of the Authority shall—
(a)give written notice of any casual vacancy among the London members to the Greater London returning officer; and
(b)give public notice of any casual vacancy among the constituency members.
(3)Any public notice under subsection (2)(b) above shall be given—
(a)by posting the notice in some conspicuous place or places in the Assembly constituency concerned; and
(b)in such other manner, if any, as the officer considers desirable for giving publicity to the notice.
(4)Any notice under subsection (2) above shall be given as soon as practicable after the date on which the vacancy is to be regarded under subsection (1) above as occurring.