President P.W. Botha's new plan to expand blacks' political role was denounced Friday as vague and inadequate, but even some critics credited him with courage.

For all their limitations in the eyes of black activists, the proposals sent a clear message to extreme-right whites that Botha was willing to risk their wrath in pursuit of his version of reform.Parliament members of the far-right Conservative Party, victor over Botha's National Party in three recent elections, depicted the president's plan as dangerous and said he was "selling out the white man."

"Black power is lying in wait for you," said the Conservatives' leader, Andries Treurnicht. "You're walking straight towards it."

In a speech to Parliament on Thursday, Botha proposed black participation in Cabinet-level policymaking and on the electoral college that selects the president. He suggested that blacks, who now may vote only in local elections, could select their representatives in regional balloting.

Black and white moderates criticized Botha's vagueness and his reluctance to bring blacks into Parliament. But they praised his willingness to challenge the far right, which consists primarily of the president's fellow Afrikaners.

"As limited as the state president's thought is, it will be used against him by the far right, which he now tentatively begins to defy," said Zulu leader Mangosuthu Buthelezi.

Colin Eglin, leader of the anti-apartheid Progressive Federal Party, softened his usual denunciations of Botha to say his party, although skeptical, wished the president success in starting negotiations with leaders of the nation's 26 million blacks.

By law and custom, apartheid establishes a racially segregated society in which blacks have no vote in national affairs. The 5 million whites control the economy and maintain separate districts, schools and health services.

More militant anti-apartheid leaders were unimpressed by Botha's speech, which did not address blacks' fundamental demands for full voting rights and abolition of apartheid laws.

Anglican Archbishop Desmond Tutu described Botha's proposals as "slight adjustments to the evil system" of apartheid.

It won't help if the government merely "moved furniture around, because the room would remain the same," Tutu said at the close of a four-day visit to Britain.

"Reform will not come by `big master' throwing to us crumbs of conscience that fall from his table," the black archbishop said. "It will happen when all the people in South Africa are able to determine the menu together when they sit at the same table."

Botha, returning to Parliament on Friday to explain aspects of the presidential budget, veered from his text to defend his political proposals.

Blacks, he said, "cannot be wished away abracadabra" as the conservatives might hope. He said blacks would have to be brought into the government and given a voice in choosing a president.

But Botha also stressed that white voters have a say on the proposal to include blacks in the electoral college.

A referendum on this issue would present whites with a clear choice between the National Party and the Conservatives.