The Senate drew its membership from elected representatives of each of 40 Districts and Nairobi area, that had been curved out by the Royal Boundaries Commission:
36. (1) Kenya shall be divided into 40 Districts and the Nairobi Area; and each District and the Nairobi Area shall elect one Senator ....... .
The First Senate was in all intents and purposes, no more than a House of tribal representatives. According to Proctor, these 40 Districts were curved and defined in such a manner as to make .......the senate constituencies more homogeneous tribally and thus provide more nearly—although still not perfectly—for the representation of tribes as such in the upper chamber. In thirty-five of the forty-one constituencies, one tribe constituted an absolute majority of the population and in seventeen districts over 90 per cent were of the same tribe!" (Proctor, 1965).
Interestingly, KADU's proposal at the Lancaster House conferences had been for a senate that would be equal in power to the lower house, consisting of 5 members drawn from every one of the seven Regional Assembly. KADU further wanted an arrangement in which these senators would be chosen through nomination by their respective Regional Assemblies and not through universal suffrage. KADU's wish was however no granted and so the Senators had to secure their seats via elections in 1963:
35. The Senate shall consist of 41 Senators, elected in accordance with the provisions of section 36 of this Constitution.
The Senate was led by an elected Speaker and Deputy-Speaker:
43. (1) There shall be a Speaker of the Senate who shall be elected by the Senate from among the persons who are Senators or are qualified to be elected as such.
44. (1) There shall be a Deputy Speaker of the Senate who shall be elected by the Senate from among Senators other than Ministers and Parliamentary Secretaries.
Senators were to serve for a six-year term, meaning that the election of members to the Senate ran on a different election calendar from that of the members to the House of Representatives:
42. (3) A Senator shall vacate his seat at the expiration of six years beginning with the date of return of the first writ returned at the general election of Senators at which he was elected, and his term of office shall not be affected by the dissolution of Parliament: ...... .
The same is echoed by Proctor, "It was also agreed readily that a Senator's term should be fixed for six years and that the life of the Senate would not be affected by the dissolution of the House of Representatives or the fall of a Government. This provision meant, as Mr. Mboya pointed out later, that "changes in the mood of the electorate will not be reflected so quickly in the composition of the Senate
as in the composition of the House of Representatives" and was intended to
enable Senators to "achieve a degree of detachment from the more violent
fluctuations of political mood and party politics." The chances of fluctuation were further reduced by the provision that the expiration of the members' terms would be staggered so that no more than one-third of the seats would fall vacant at any one time." (Proctor, 1965).
Naturally, a member elected to fill a vacancy (in a by-election) had to vacate their seat at the next election of Senators:
42. ....... Provided that: (a) a Senator who was elected to replace a Senator who has died or ceased to be a Senator before the expiration of his term shall vacate his seat at the expiration of the remainder of that term; and (b) a Senator who was elected to fill a vacancy that was left unfilled at a general election shall vacate his seat on the date on which he would have vacated it if he had been elected at that general election.
This representation formula of a Senator per every District, soon became a point of controversy since sparsely populated Districts and language people (tribes) were over-represented in the upper house. Furthermore, the idea of Districts denied white settlers and Asians any direct representation in the Senate. KANU was not unduly concerned by this (especially in regard to over-representation) because the powers of the Senate were in any event, significantly diminished. However, looking at the numbers, J H Procter provides an example that demonstrated the lopsided nature of representation in the Senate: "In the twenty-eight contested Senate constituencies, KANU polled a total of 1,028,906 votes and won thirteen seats, while KADU polled 474,933 votes and won twelve seats. The population of the five districts in which KANU candidates were unopposed was 880,000 while the population of the four districts which returned KADU candidates without contest was 351,800. Thus it could be said that on the average each KANU Senator had received the support of approximately twice as many voters as had each KADU Senator" (Proctor, 1965).