A U.N. plan for a peaceful transition to independence in the territory of Namibia (Southwest Africa), which was to be set in motion today, faced a setback with the rejection of two key provisions in the plan by South Africa.

South Africa advised U.N. Secretary General Kurt Waldheim that it could not accept the clause allowing guerrillas of the South West Africa People's Organization (SWAPO) to be quartered inside the territory during the U.N.-supervised election campaign. It also objects strongly to the absence of any U.N. monitoring of SWAPO bases established in the neighboring countries of Angola and Zambia.

The South African government appears to be strongly opposed to both these provisions and unlikely to agree to the U.N. plan unless they are altered or deleted.

Meanwhile, political parties alled with South Africa within the territory are pressuring the South African government to opt out of the U.N. plan. Those parties, acting in the constituent assembly, a local body elected in a South African-supervised election last December over objections of the United Nations, today declared that if the U.N. plan was not launched by March 15, it would "consider the necessary steps to lead Southwest Africa to independence."

This is interpreted here as signaling the intention of setting up an independent government in the territory without U.N. sponsorship and therefore unlikely to get international recognition. Such action would also mean a continuation of the guerrilla war between South Africa and SWAPO in Namibia.