Johannesburg — ''Won't the government return to a more conservative stance if it gets a 'no' vote?'' asks the young white liberal in anguished tones. ''And what will people overseas think?'' he wonders, ''if whites turn down a modest step to broaden South Africa's white-minority government.''
These are treacherous times for South Africa's liberal white establishment. From the highest corridors of power to the family dinner table white South Africa is talking about reform as never before.
But those who have fought long and hard for fundamental change in South Africa - like those at a recent meeting of the Institute of Race Relations, where these questions were asked - are distraught and defensive.
For them, the reform proposal that will go before white voters early next month is a fraud. They worry that, if it is passed, it could deal a devastating blow to white liberalism in South Africa, strengthening the view among the black majority that it is pointless to look to the white community for meaningful nonviolent change.
The young man at the Institute of Race Relations meeting was expressing two common fears about the consequences of a ''no'' vote in the coming referendum. The vote will test the government's proposed new constitution, which would bring Coloreds (persons of mixed race) and Indians into Parliament. The plan would continue to exclude the black majority from the assembly.
White liberals who feel the new constitution is a retrogressive step are fighting an uphill battle. Arrayed against them are some other white opponents of the government who say that the new constitution would lead to inclusion of blacks or that the right wing would benefit from a ''no'' verdict.
Frederik Van Zyl Slabbert, leader of the relatively liberal opposition Progressive Federal Party, says the government has created in the minds of the white electorate the feeling that at least this is a step in the right direction. And more and more whites who have never supported the government are writing their own hidden agendas into this constitution.
Mr. Van Zyl Slabbert admits the rank-and-file members of his own party are divided and that it will be difficult to defeat the new constitution. In an interview he explained his belief: The real issue in South Africa is black-white coexistence. And the willingness to negotiate stands a better chance of surviving with a ''no'' vote.
That is because, in his view, blacks correctly read in this new constitution the final enshrinement of their exclusion from central government.
John Kane-Berman, director of the Institute of Race Relations, agrees. He told an audience that Africans have not been omitted, but deliberately placed outside the proposed constitution.
Mr. Kane-Berman says approval of the new constitution will be seen by the government as a broad white endorsement of the full agenda of apartheid. For the constitution to gain approval, most analysts say, large numbers of the country's English-speakers will have to cross over and support the ruling Afrikaners.
Indeed, in justifying the exclusion of blacks from the new constitution the government says the blacks are progressing along a different route.
That route is the 10 tribal ''homelands'' set up by the government to remove blacks from the mainstream of the country. The hidden agenda that many whites see is a government attempt to deal with so-called urban blacks, who will never return to these homelands.
The other argument that is apparently persuading many reform-minded whites to vote for the constitution is that regardless of government intentions, the constitution will for the first time involve the ruling National Party in multiracial governing, albeit in a segregated parliament. Many feel this should be grabbed and exploited.