For the purposes of this Part as it applies in relation to a principal council for an area in England, the three options for the scheme for the ordinary elections of councillors of such a principal council are those set out in this section.
The first option is for a scheme under which—
the term of office of councillors is four years,
the elections are held in a given year and every fourth year after it,
all the councillors are elected in each year in which the elections are held, and
the councillors retire together.
The second option is for a scheme under which—
the term of office of councillors is four years,
the elections are held in a given year and every second year after it,
one half (or as nearly as may be) of the councillors are elected in each year in which the elections are held, and
one half (or as nearly as may be) of the councillors retire in each year in which the elections are held.
The third option is for a scheme under which—
the term of office of councillors is four years,
the elections are held in a given year and every year after it other than every third year after it,
one third (or as nearly as may be) of the councillors are elected in each year in which the elections are held, and
one third (or as nearly as may be) of the councillors retire in each year in which the elections are held.