Students in Soweto, Johannesburg's troubled black township, have launched a new and highly sophisticated campaign against black government employees, pressuring them - often, allegedly, under threat of violence - to quit jobs that are involved with the white power struggle. The move is aimed at crippling white rule by taking away the massive numbers of black employees needed to support it.

Political observers and newpapers editorials here have already heralded the campaign as the opening of a new phase in the black political struggle that began June 16 of last year. The impact already ahd been impressive, both strategically and psychologically.

The effort, headed by the Soweto Student Representatives' Council, opened about two months ago when students urged members of the Soweto Urban Bantu Council to resign. The Urban Bantu Council, which students called the "Useless Boys' Club," was a black advisory body to the white board that administers the sprawling township of more than 12 million Africans.

The campaign worked: The vast majority of the 41 members quit last month. The government was forced to acknowledge the action, suspending the body and leaving white administrators without official black liaison with the township.

Students have now stepped up their pressure tactics against government institutions, spreading the campaign to include school boards and black teachers, African policemen and selected leaders of the nine tribal reserves or homelands scheduled to gain independence from South Africa in the near future.

There are growing signs of adult backing, especially from the Soweto Committee of Ten. made up of prominent black professionals who are attempting to fill the power vacuum created by the Urban Bantu Council's collapse. Headed by Dr. Nthato Motlana, a Soweto physician, the committee has drawn up a blueprint for a new community board that would have total autonomy over Soweto, including power over education, police and local elections.

The committee has held lengthy talks with the students, and reportedly does not make a major move without student backing.

Together, the two forces are attempting to block the government's proposed new Community Councils, which would replace the Urban Bantu Council, but allow black members only limited powers - such as garbage collection, administration of sports facilities and libraries and renting government-owned homes.

According to one African member of the Soweto Student Representatives' Council the youths are using their growing power to weaken the existing government institutions for blacks, while the committee is working to construct an alternative, which Dr. Motlana has said he will discuss only with the prime minister John Vorster.

Students have recently been applying the heaviest pressure on the 19 black school boards in Soweto, urging members to stop supporting a system that legally endorses a double standard of education for blacks and whites. Poor black education has been one of the key complaints of the youth movement, often sparking off massive school boycotts and disorders.

Although white school officials have tried to deny it, several members of Soweto school boards say they have resigned - although there is some doubt about their motives.

Meadowlands school board member, H. Pele. reported gave "contamination" of black youths by the current educational system as the reason for his resignation. Members of the Zhosa West School board wrote, however, of the compulsion to resign "in face of decided threats to [our] lives."

Members of the youth group, all unwilling to be quoted for fear of government retribution, also passed the word around Soweto that the roughly 4,000 black teachers should resign in September, after collecting their annual bonus checks.

One teacher at the Sele Secondary School reported: "Several of us have been told to prepare to resign in September." He added that he and several of his colleagues would do as the students instructed.

[In a related development, black students boycotted about 20 secondary schools in two townships outside Pretoria, 30 miles northeast of Johannesburg, new agencies reported. The students were protesting the quality of education for blacks.]

The latest target in Soweto is black traffic policemen, who have been given an ultimatum to stay off the road as on today or face trouble. There are reports that the students also plan to urge all black members of the South African police in Soweto to resign. There are more than 1,800 black policemen.

The Soweto police chief. Col. Jan Visser, admitted today that militant students hope to force blacks on government bodies to quit. He warned, however, that we will defend ourselves at all times and take any necessary steps if threatened.

"Nothing good will be achieved by intimidation. It's a furtile exercise which can only produce ill feelings . . . My advice to the dissidents is to hold a lawful meeting to iron out their grievances," Visser added.

Over the weekend, students and 12 other black-consciousnes groups extended the campaign to include the tribal homelands, releasing the text of a warning issued to Chief Lucas Mangope, of the Bophuthatswana homeland, scheduled for independence on Dec. 6.

Under South Africa's apartheid policy, all 18 million Africans will become citizens of their respective tribal homelands upon independence, making them aliens in South Africa.

Many African groups have protested the move, since more than 80 per cent of South Africa's population would technically be forced into only 13 per cent of the land, a move that will also deprive them of the riches they say belong to them just as much as to the 4.2 million whites.

The message to Mangope warned him "not to sell the souls of his people" by accepting independence. Mangope is scheduled to meet with the prime minister and his staff on Wednesday to discuss the final issues paving the way to independence.

The militancy and determination of the students was displayed in an incident earlier this month, when black youths stoned a car carrying three black beauty queens to a contest. The women were charged with being sellouts to the black community, and police eventually used teargas to disperse the mob.

The appeal to allow Soweto residents to run their own affairs had picked up support among moderate politicians and English-language newspapers. The Johannesburg Rand Daily Mail recently editorialized:

"The prime minister had stated his government's firm belief in a people's inalienable right to decide their own future for themselves. Surely the same principle must apply to Soweto. It, and not a group of government officials, should decide who its leaders should be and how to choose them."

On Sunday, the Committee of Ten is to hold a public meeting at a Soweto Catholic church to lay out its plans for a new independent governing board. The next step, according to Dr. Moriana, is to take the appeal to the prime minister Political observers here doubt, however, that government officials at the level will agree to a meeting.