Fate of S. Africa opposition group hinges on major treason trial. Movement leader's testimony may set stage for official ban

South Africa's biggest treason trial has entered a critical phase which could well determine not only its outcome but the fate of the country's largest extra-parliamentary opposition movement. The key phase is marked by the presence in the witness box of Popo Molefe, general secretary of the opposition United Democratic Front (UDF), as a central witness for the defense.

As a UDF office holder, Mr. Molefe's testimony is considered crucial to the treason charge. The charge alleges he and 18 other men conspired with the outlawed African National Congress (ANC) and its ally, the South African Communist Party, to overthrow the government.

Associated with that accusation is another: that the UDF was formed at the behest of the ANC as a front to further its aims.

A guilty verdict would provide judicial substantiation of political charges that the UDF is a revolutionary organization linked to the outlawed ANC. It could set the stage for the banning of the UDF and, at the same time, arm the authorities with the justification they need to silence Western criticism.

The state's charge of treason rests in large measure on the contention that the UDF was formed in response to a call on Jan. 8, 1983, by the ANC president, Oliver Tambo, for the formation of a united front.

But Molefe told the court he had called for a united front in May 1981, more than 18 months before Mr. Tambo's call.

He did so in an address to the South African Council of Churches, declaring: ``Having experienced an unfortunate and sordid chapter in our history ... a chapter characterized by treachery and betrayal, greed, hypocrisy and blunder, a united front becomes an imperative in our chief endeavours to meet the demands of our time.''

Molefe's time in the witness box comes on the eve of the fourth anniversary of the founding of UDF on Aug. 20, 1983. He was detained with the UDF's publicity secretary, Mosiuoa Lekota, in April 1985.

In the months between the launch of the UDF and the detention of Molefe and Mr. Lekota, the UDF grew rapidly into a huge, formidable coalition of more than 600 anti-apartheid organizations, representing an estimated 2 million people. But since their arrest, the UDF has seen hard times.

Thousands of UDF officials and activists have been detained under the two states of emergency declared since then, the most recent of which was renewed on June 12.

The Detainee Parents' Support Committee, a civil rights organization, estimates that three-quarters of all emergency detainees are members of the UDF or its affiliates.

Only last month the two men who took over from Molefe and Lekota, Mohammed Valli and Murphy Morobe, were detained. Their internment ended months of shadowy existence, when they operated clandestinely, never sleeping in the same place for more than a few nights, in a desperate bid to maintain an active UDF presence in the political arena.

Last October the authorities prohibited the UDF from receiving overseas funds. At the time the UDF national treasurer, Azhar Cachalia - who has himself been detained several times - estimated more than half the UDF's funds came from foreign donations.

With most of South Africa's wealth in white and therefore conservative hands, organizations seeking radical change are dependent largely on foreign funding for financial viability.

There also has been a rise in black vigilante movements against the UDF. With the alleged connivance of the police, they have hounded UDF activists out of many black townships or, at the least, driven them underground.

The vigilante groups also are alleged to be linked to anonymous death squads which have hunted down and killed UDF leaders.

The extent to which the UDF has suffered a major setback at the hands of allegedly state-sponsored vigilantes is starkly manifest in Kwanobuble, a black township near the eastern cape town of Uitenhage. Once a UDF stronghold where even armed policemen moved warily, the township is today largely controlled by vigilantes.

The only positive development for the UDF has been the formation of the South African Youth Congress, its newest and potentially most powerful affiliate, and the bold way in which the Congress of South African Trade Unions has taken up political issues on behalf on the harassed UDF.

Journalists in South Africa operate under official press restrictions.