JOHANNESBURG, South Africa -- Startled by his party's loss to apartheid forces in a local election, President F. W. de Klerk put his career and his country's movement toward the end of apartheid on the line yesterday by calling for a nationwide vote of confidence by white voters.
The announcement, made one day after Mr. de Klerk's ruling National Party lost an important election to its right-wing opposition, was a high-stakes gamble designed to make it clear which party speaks for whites on the issue of South Africa's future.
Mr. de Klerk said he would step down and his government would resign if he were to lose the referendum, which is to be held within the next six weeks.
If Mr. de Klerk wins, his government can confidently pursue reforms aimed at ending apartheid and continue negotiations with the black majority on a new constitution. But if he loses, the entire reform process may be thrown into turmoil and South Africa may suffer a serious setback in its efforts to regain international respectability and internal stability.
"This is something which must be settled," Mr. de Klerk said in a speech to Parliament, which is meeting in Cape Town. "It is in the interest of the negotiation process itself that we settle this question."
He said the referendum is necessary because the opposition Conservative Party claims to represent the majority of white voters. "It's that claim on which these voters must now give a verdict," he said. "It's a question of credibility.
"If I lose the referendum, I will resign, the government will resign, and there will be an election."
Mr. de Klerk was dealt a major political blow Tuesday when the National Party lost a crucial parliamentary election in the town of Potchefstroom. His latest move was a clear and bold attempt to rescue the political initiative from that defeat.
"He wants to put it beyond doubt that he has a mandate in the face of the election defeat," said Sheila Camerer, a member of Parliament and a representative of Mr. de Klerk's National Party.
Mr. de Klerk said he was confident he would win a referendum, but political analysts were less certain. "If I were a gambling man, I wouldn't put terribly much money on it. It could go either way," said David Welsh, a political science professor at the University of Cape Town.
"But I think de Klerk will win -- not by a comfortable margin, but by a workable margin," he said.
The South African president did not say specifically what question he would put to white voters, but he said the issue is whether white voters want his government or the Conservatives to represent them in deciding the country's political future.
The Conservative Party, having won decisively in Potchefstroom and wrestled away a seat the National Party had held for decades, claimed its victory was proof that whites do not want the new South Africa that Mr. de Klerk is negotiating.
The Conservatives charge that white voters who elected Mr. de Klerk in the first place never gave him a mandate for the changes he has made since coming to power in 1989: lifting bans against the African National Congress and the South African Communist Party, releasing thousands of political prisoners, repealing apartheid laws and negotiating a new constitution with blacks.
The right-wing party has opposed those reforms and instead supports the idea of a white "fatherland" where blacks would have no political rights. But before it could create this -- in effect a re-creation of old-style apartheid -- the Conservatives would first have to win both the white referendum and an election for a new government.
The election in Potchefstroom was considered a strong indication that the ruling National Party has lost significant support from whites who voted Mr. de Klerk into office in
1989. But Mr. de Klerk is believed to have picked up the support of liberal whites in the last couple of years.
While Mr. de Klerk said a referendum was needed to continue with the reform process, the ANC, headed by Nelson Mandela, said a referendum would delay "movement toward peace and justice for all our people."
The ANC said it rejected the notion of a racial referendum "or any exercise aimed at giving whites a veto over the future of our country."
In a joint statement with its Communist and trade union allies, the ANC said that "a whites-only referendum is not only the hallmark of racism but also has the effect of delaying movement toward peace and justice for all our people."
The government and the ANC have been the most important players in the reform process. The ANC is the largest and most influential black organization in the country.
It led a highly successful campaign for international sanctions against South Africa to protest apartheid, the system of racial repression in which 5 million whites ran the government and 30 million blacks were denied the vote.
Since Mr. de Klerk initiated his reform program and began talks with the ANC and other black groups, most countries around the world have lifted trade and economic sanctions against South Africa.
If the process of reform were to end, so might South Africa's impressive progress in regaining international respect and much-needed foreign investment.
The United States lifted the Comprehensive Anti-Apartheid Act last year, removing sanctions on most trade and new investments.
Only Wednesday, speaking to businessmen in Nashville, Tenn., President Bush said he had issued a presidential order finding that "significant progress toward the elimination of apartheid has been made in South Africa."
The United States withheld any judgment of Mr. de Klerk's decision to call for a referendum yesterday, saying it was an internal matter.
"We continue to support fully the Convention for a Democratic South Africa process as the appropriate forum for discussions on South Africa's future. The specifics of the transition to a new constitution are for the people of South Africa to decide among themselves," said State Department spokeswoman Margaret Tutwiler.
Formal negotiations on a new constitution began in December between the government and 18 political organizations representing every racial group in South Africa. The second round of talks is scheduled to begin at the end of next month.
Mr. de Klerk has said he wants to hold the white referendum before that round begins.
Political reforms made by President F. W. de Klerk since he took office in September 1989:
APARTHEID LAWS: Repealed all major laws on separating whites and blacks, including segregation of residential areas and a ban on blacks' owning land in most of the country. Blacks still cannot vote in national elections, and education remains largely segregated.
OPPOSITION GROUPS: Legalized dozens of opposition groups, including the African National Congress and the South African Communist Party. Released black leader Nelson Mandela and other leading opposition figures from jail.
CONSTITUTIONAL TALKS: Is negotiating with the ANC and other groups on giving the vote to blacks. His goal is to establish a non-racial democratic state with protection for whites and other minorities from domination by the black majority.