The South African government is being accused of failing to honor a pledge to restore citizenship rights to millions of blacks who became aliens when four tribal regions were granted nominal independence under the country's apartheid system of racial segregation.

Official statements during the past week have indicated that South African citizenship will be restored to only about 1.75 million of the estimated 10 million blacks connected to these regions, called "homelands." The rest will be treated as aliens requiring special permits to live and work in South Africa.

Civil rights workers say this effectively means the influx control system, which the government claims to have abolished, will remain in force for millions of blacks and that hundreds of thousands of homeland residents will fail to get permission to work in the industrial cities.

They say that to enforce the system, the police will have to stop blacks on the street and demand to see their personal documents, effectively continuing the "pass law" raids that also are supposed to have been abolished.

Opposition sources are now accusing the government of a "massive breach of faith" in its pledges earlier this year to abolish these controls starting July 1. The laws themselves have been repealed but, these sources say, the controls will continue in other forms for many blacks.

The scrapping of the pass laws and influx control has been widely acclaimed as one of the most important reforms introduced by the administration of President Pieter W. Botha. Botha emphasized it in a series of signed newspaper advertisements last February that claimed that "a new era of freedom has begun."

President Reagan also cited it in his July 22 policy speech on South Africa as evidence that the Botha administration had brought a "dramatic change" in South Africa. "Citizenship, wrongly stripped away, has been restored to nearly 6 million blacks," Reagan said.

Now, by the government's own estimate, it seems that fewer than one-third of that number will benefit from the restoration. Civil rights workers say between 7 million and 8 million other blacks, including many who commute daily to work in the Johannesburg-Pretoria area from townships that are technically in a homeland, will be worse off than before.

Those blacks who have not been assigned a tribal homeland -- about 19 million -- have however, won much greater freedoms of movement.

For the many others, the situation will be further aggravated in December when a fifth homeland, KwaNdebele, just north of here, becomes nominally independent. Hundreds of thousands of workers who commute daily from there into this industrial heartland of South Africa will then also become aliens, requiring work permits to enter the country.

Sheena Duncan, a key figure in the Black Sash civil rights organization, which specializes in fighting the influx control system, pointed out that by law aliens cannot be granted work permits unless there is a shortage of South African citizens available in their job categories.

Because there is massive black unemployment at the moment, rising to nearly 50 percent in some areas, this means few of the homeland aliens will qualify for work permits, Duncan said.

Johan Pretorius, director of migration at the Department of Home Affairs, confirmed at a news conference in Pretoria Thursday that the government's priority would be "to protect employment opportunities for its citizens," excluding the homeland aliens.

Duncan also believes that what she calls the "hassle factor" of obtaining work permits and subsequent extensive paperwork involved in employing aliens from the independent homelands will cause employers to avoid them and hire workers with citizenship rights instead.

"With all the bureaucracy involved, the homelanders are going to find it much harder to get jobs, and unemployment in those regions is going to soar," Duncan said.

But this will not show up in South Africa's official statistics because the homelands are regarded as foreign countries. Statistically, Duncan points out, government employment reports will reflect an apparent improvement because more citizens will be employed at the expense of the homelanders.

The opposition Progressive Federal Party maintains that the government gave an informal undertaking when the reform bills were being studied by a parliamentary committee earlier this year that workers from the independent homelands would be exempted from the Aliens Act, which requires foreigners to get work permits.

"There has been a clear breach of an undertaking given by government officials in the standing committee," said Nic Olivier, the party's chief research officer and a key member of the opposition team in the committee.

But officials say they are doing no more than spelling out the implications of legislation passed by the white-dominated parliament. Duncan agreed. "We have been pointing out all along that too many people were exaggerating what was being done instead of looking at the fine print of the law," she said.

This underlines a complaint made frequently by people like Duncan, that in their eagerness to find cause for optimism in the South African situation, many concerned observers, including outsiders like President Reagan, often read more into Pretoria's stated intentions than is justified.

But Duncan is careful to give credit for what has been done. The changes to the pass laws and influx control regulations, she said, have meant a "marked improvement" in the circumstances of two-thirds of South Africa's total black population of 28 million.

For the 19 million who do not belong to the tribes that have nominally independent homelands, there is now much greater freedom of movement. These blacks no longer need official permission to work anywhere they like in South Africa, and they are free to go anywhere in the country to look for work, which they were not allowed to do before.

However, they are still restricted by residential segregation laws to living in townships demarcated for blacks only, and they can use only segregated state institutions such as schools and hospitals. They must also have "house permits" showing that they are authorized to live in a particular house in the segregated townships.

But for all except the estimated 1.75 million of the 9 million members of the Xhosa, Tswana and Venda tribes that have independent homelands, life will be more difficult than before, Duncan said.

Under the old system, every black person was required to carry a pass at all times and could be arrested if he or she failed to show it to a police officer on demand. Pass raids were commonplace, and more than 2,000 blacks were arrested every day.

The "passes" certified that the black person was entitled to be in what is officially regarded as white South Africa -- the 87 percent of the country reserved for occupation by the white minority of 4.6 million and in which the smaller colored (mixed race) and Asian minorities recently have been granted subordinate political rights.

The 28 million blacks were assigned to 10 small and fragmented tribal homelands, whether they lived there or not. These regions together make up the remaining 13 percent of South Africa's land area and exclude all the industrially developed areas.

Blacks could gain the right of permanent residence in "white" South Africa, where all the jobs are, if they were born there, if they worked there for the same employer for 10 consecutive years or if they worked for different employers for 15 years without a break.

Any other black person could be in white South Africa only as a migrant laborer, working on a renewable one-year contract and leaving his family behind in the tribal territory.

The homelands, meanwhile, were scheduled for nominal independence. As each was granted independence, beginning with the Transkei in 1976, all members of the tribe involved, whether they lived in the homeland or not, forfeited their South African citizenship and became citizens of the new homeland state, which was not internationally recognized.

The political objective, explained repeatedly by government spokesmen, was that when all the homelands were independent there would no longer be any black South Africans. Although the country would still have an overwhelming majority of blacks living and working in its metropolitan areas, they would all be statutory foreigners. Legally, South Africa would have had a white majority of citizens with mixed-race and Asian minorities.

In the face of increased black urbanization and the refusal of several of the generally conservative tribal chiefs to accept independence, the Botha administration decided this was not a viable solution to South Africa's race problem.

It began reforming the policy, recognizing the permanence of what are termed "urban blacks" and giving them a better deal socially, economically and politically. But in the phrase of Hermann Giliomee, a leading Afrikaner political scientist, the reforms are aimed at "sharing power without the whites losing control."

The scrapping of the pass laws and influx control and the restoration of citizenship to those homelanders already stripped of it have been the main features of this limited reform program.

As government spokesmen have explained in statements and at news conferences during the past week, blacks officially classed as citizens of the independent homelands who are not "permanently resident" in the white sector will not qualify for the restoration of their South African citizenship. These are the people who will be classed as aliens and must get permits to enter South Africa, which cannot be issued if there are enough citizens to do their kind of work.

The crunch issue, said Duncan, is the definition of "permanent residence." This is not clearly spelled out in the law. Dirk Vermeulen, a senior official of the Department of Home Affairs, said at a news conference in Pretoria Thursday that migrants and those who lived, worked and studied in South Africa while their families lived in the homelands would not qualify as permanent residents.