Windhoek, Namibia — Ben Africa looks out on a town hall audience that is mainly black and poor - many still dusty from a morning of work. ''The hour of reckoning could be in sight,'' he tells the delighted crowd of Rehoboth Basters, one the ethnically defined population groups in Namibia (South-West Africa).
Mr. Africa, a prominent black politician here, is speaking of independence for Namibia. Political jockeying for an election has already already begun.
The Western ''contact group'' (the United States, Canada, Britain, West Germany, and France) has already presented, through representatives, its new proposals for independence to the various political factions here. The group itself arrives in Windhoek Oct. 29 to talk about the broad constitutional guidelines for a future independent Namibia. The new proposals call for:
* An elected constituent assembly that would ensure ''fair representation'' of different political groups - perhaps on a proportional basis.
* A constitution that sets up three branches of government - legislative, independent judicial, and executive.
* Provisions for changing the constitution by a ''designated process'' of the legislature or votes in a popular referendum.
* A declaration of fundamental rights, including ''protection from arbitrary deprivation of private property.'' These rights will be consistent with the United Nations Universal Declaration of Human Rights.
* Constitutional ratification by two-thirds vote of the constituent assembly.
The contact group revised its original proposals for Namibian independence in response to South Africa's concern that the territory's white population be protected under any future black government. South Africa has administered Namibia since 1920; 11 percent of the population is white.
Namibia's political parties see the guidelines as assurance of a role in a future government, should SWAPO (South-West Africa People's Organization) win an election. From bases in Angola SWAPO has long waged a guerrilla war for independence.
For South Africa and the Namibian political parties, United Nations impartiality will prove the stickiest issue in the independence negotiations. UN Resolution 435 is the framework on which Namibia will gain independence. UN plans call for free elections under UN supervision. But South Africa and the territory's internal parties say the UN is not impartial, having long ago recognized SWAPO as the ''sole and authentic'' representative of Namibia.
Despite what is almost sure to be general support for the contact group proposals here, there is growing strain between South Africa and the internal political parties that could bog down a settlement.
No one doubts that South Africa has reserved for itself the right, in the end , to decide whether Namibia moves toward an election for independence. But South African political developments make it increasingly clear that Prime Minister P. W. Botha is not apt to go ahead with a settlement that is opposed by the mainly white internal power structure.
Mr. Botha appears increasingly sensitive to discontent within the right wing of his National Party. Political analysts feel he will resist any appearance that he has ''sold out'' white interests in Namibia.
Oddly, policies recently implemented by the South African-appointed administrator-general of Namibia appear to be strengthening SWAPO's hand. Although South Africa has permitted Namibia to move toward a more integrated society, the process by most accounts has stalled, providing SWAPO with valuable ammunition.
''We are not seen to be governing effectively,'' concedes Ben Africa, vice-president of Namibia's most powerful internal political alliance, the DTA (Democratic Turnhalle Alliance).
As the only apparent alternative to SWAPO rule, the DTA has in the past had the tacit support of South Africa. However, a conservative trend among Namibian whites seems to have caused a certain parting of the ways.
Observers think South Africa may have come to see the DTA as a loser in an election. Still, analysts do not think South Africa will be able to go into an election with vocal opposition from the DTA.
DTA chairman Dirk Mudge says, ''I cannot go into an election with the appearance of being a South African stooge,'' he adds, making clear the DTA wants some policies changed.
Even if South Africa wants to bolster the DTA before an election, analysts here agree it will be difficult.
In a recent regional vote, the white election was won by Kosie Pretorius's South-West Africa National Party, the Namibian equivalent of the ruling party in South Africa. Mr. Pretorius rejects at the outset the principle that there should be a one-man one-vote election in Namibia.