Near the end of May, Angolan President Agostinho Neto accused two members of his ruling Popular Movement party of criticizing the government behind its back by "holding [their] ideological debates in the bedroom." The two were then expelled from the party's Central Committee.

Only six days later, the two dissidents sets aside their clandestine "bedroom" opposition to the government and led an eight-hour bloody coup attempt that severely shook Neto's government and left hundreds, including seven top government and military officials, dead.

The attempted coup was the most serious blow yet to Neto's government, which has been trying to extricate itself from an economic quagmire and to eliminate the anit-government guerrilla activities in the north and southeast of Angola that have persisted since the Popular Movement came to power in November 1975 with the military backing of some 15,000 Cuban troops supplied with Soviet arms.

Neto's Popular Movement emerged victorious over two Western-backed opposition groups, the National Front and the National Union (UNITA), in Angola's three-way civil war from August 1975 to March 1976.

For Angola, the aborted putsch is going to mean, according to Neto himself, a harsher, more repressive regime.

"It is clear that all this must influence the behaviour of the leadership - the leadership of the country, the Popular Movement leadership and the leadership of the Angolan state," Neto said after the coup attempt.

"We aren't a bourgeois democracy in which each one comes with his theory to tell us what we can do . . . We will have to redo everything . . . From the day fo the 27th, . . . therefore, the dictatorship [will be] a little more strong," he explained.

As for the participants in the coup, Neto said, "We are not going to use the usual methods" of trial, warning that they would be severely punished.

For the Cubans, the attack on Neto's leadership will undoubtedly delay the departure of their troops from the trouble African country where Cuban national prestige rides on the success of Neto's government. Gen. Raul Castro, Cuba's defense minister and No. 2 man in the Cuban Communist party, visited Angola in early June.

The Cuban presence in Angola led to a reversal of the warning trend between the United States and Cuba in 1975, and the Carter administration maintains that Cuban intentions in Africa are still an important factor to be settled before relations with Cuba are normalized.

As for Neto himself, the abortive coup represents a setback in his efforts to demonstrate to Western powers that he and his movement are Angola's legitimate rulers.

"We're just digesting all this to see what is Neto's relationship to the Popular Movement, the Movement's to the government and the government's to the whole country," said a U.S. official.

The apparently well-planned but badly executed putsch attempt was led by former Interior Administration Minister Nito Alves and a former army political commissar, Jose Van Dunen.

Joining Ales and Van Dunen were two members of the army chiefs of staff, Jacob Caetano, also known as "Immortal Monster" and Bakalov, a Soviet-trained black who was one of the judges presiding at the trial of American and British mercenaries last year.

The minister of commerce, David Aires Machado, and five of the country's 16 provincial governors were also implicated in the plot. According to Neto, there were clandestine supporters of the coup in the army, the Popular Movement's youth group, its women's auxiliary and the labor unions. Yet, despite this widespread support, the people failed to spill into the streets on the day of the coup to back the overthrow attempt.

Also conspiring with the Alves-Van Dunen faction was a small group of Portuguese and white Angolans who had been active in the Portuguese Communist Party until they were repudiated by its leader, Alvaro Cunhal, according to reports published by the Third World magazine Afrique-Asie.

The magazine relates that these people came to Angola as Portuguese Communists in 1974 and attempted to influence the Popular Movement by making it "more dogmatic, even Stalinist." Among them was Cita Valles, an Angolan-born Portuguese woman who married Van Dunen and played a major rule in organizing the aborted coup, according to the Neto government.

The division between the Alves-Van Dunen faction and Neto's group began to appear in 1974, according to Afrique-Asie. In a party congress that year the dissidents opposed giving citizenship in an independent Angola to any of the 400,000 Portuguese living in the country unless they had actively participated in the colonial guerrilla war against Portugal.

Alves' group wanted to offer the more than 100,000 mulattos only an "option" of citizenship. Neto's government offered automatic Angolan citizenship to anyone born in Angola or living there for at least 10 years.

The Alves-Van Dunen group exploited the racial issue, clandestinely printing pamphlets that accused Neto's government of being "too light-skinned." Some of Neto'sclosest advisers and most influential men in the Popular Movement are mulattos, including the party's secretary general, Lucio Lara; Defense Minister Iko Carreira, and Economic Planning Minister Carlos Rocha.

The two groups also differed over policy toward Western investment, with Alves opposing Neto's willingness to deal with such Western Companies as Gulf Oil, to keep the door open to eventualy normalization of relations with the West and to allow the return of many Portugues technicians needed to get the economy running again.

Alves was to have become the country's president if the coup had succeeded, according to caputred putschists. His policis were clotched in a jumble of ideological jargon in which he describes the Soviet Union as the ideal state and a n example for Angola.

The attempt to topple Neto began before dawn May 27 with a attack on the Sao Paulo jail, where political prisoners are held. An armored car crashed through the front gate and the prisoners were invited to leave.

Many did, but according to Neto the two American and seven British mercenaries serving their life sentences there and members of four groups opposed to Neto's Popular Movement all refused to leave the prison.

Helder Net, a white Angolan (not related to the president) and a top official in the state's secret police, was killed at the jail by the coup-breakers.

Alives and Van Dunen were at first reported to be in the jail among the jailed prisoners, but it is now unclear where they were at the start of the coup attempt. What is clear is that the original planning and impetus for the putsch came from them and that they were at the head of operations at least by mid-morning, if not from dawn.

Alives' forces next seized the government-controlled radio station and called on the people to mass in front of the presidential palace, which is on a hill overlooking the commercial section of Luanda. Some reports say that this is where the greatest number of deaths occured, as goverment troops defended the palace against armed civilians.

Meanwhile, six Angolan officials loyal to Neto, including Finance Minister Saydi Mingas; Garcia Neto, a foreign ministry official; and four army majors were rounded up, murdered and their bodies burned in trucks later found at midday in Sambizanga, a slum suburb of Luanda.

The coup's leaders, Alves, Van Dunen, Bakalov and Valles, have all eluded capture by the government. Their pictures are printed in Angola's newspaper and wanted posters are plastered in public places. Some reports say they have escaped to Zaire.

Neto has said that in Luanda, "hundreds" have been jailed and "many others" detained in the provinces. Several Portuguese, including two former officials in the 1975 Communist-run government of Portugal, Varela Gomes and Jose Costa Martins, have also been imprisoned.

It is not clear how large a role the Cubans played in helping quash the coup attempt. Neto told his nation shortly afterward that it "is false to say that it was due to the Cuban presence in Anglola, and exclusively to that, that the bandits were crushed and will be neutralized."

It is certain, however, that Cuban troops joined government soldiers in retaking the radio station. Cuban voices were heard in the studio as the station's recapture went out live over the airwaves.

Whatever the extent of their participation, there is no doubt that the Cubans are on Neto's side.

By contrast, Neto and the Soviets have an ambiguous and complex relationship. Although Neto and his top advisers are orthodox Marxists and signed a party-to-party agreement with the Soviet Communist Party in October, they have indicated that they intend to conduct a Yugoslav-style non-aligned foreign policy.

This independence may not have pleased the Soviets, and it is believed that the Russians flirted with Alves, whose groups took a strong pro-Soviet stance and whose pamphlets accused Neto of anti-Sovietism.

While there is no clear evidence tht the Soviets had an active hand in the coup attempt in May, there are suspicions that they knew about it and let it happen.

Neto fueled such speculation by saying in a speech shortly after the coup attempt: "Some friendly countries don't agree completely with the policy of national independence" followed by the Popular Movement.

As if to silence those in Luanda who expected Neto's remarks to mark the start of a break with Moscow, the president subsequently said that the Soviet comrades were "outside this debate." Four days after the coup attempt, he felt it necessary to say, "There is no change whatsoever in our relations," with the Soviets.