2(1)On and after 1st April 1965 the returning officer for a parliamentary election for any county constituency situated wholly or partly in Greater London shall be the mayor of such London borough, or such sheriff of a county, mayor of a borough or chairman of the council of an urban district outside Greater London, as the Secretary of State may determine.
(2)Until 1st April 1965 the returning officer for a parliamentary election for any constituency situated wholly or partly in Greater London shall be the person who would by virtue of the Representation of the People Act 1949 have held that office apart from the changes of administrative areas effected by this Act.