Ryzhkov May Oppose Yeltsin for Presidency : Soviet Union: The former prime minister would accept a draft in the Russian Federation campaign. The election will be held June 12.

Former Prime Minister Nikolai I. Ryzhkov said Wednesday that he would accept a draft to run against the radical populist Boris N. Yeltsin next month for the presidency of the Russian Federation, the largest of the Soviet republics.

“Yeltsin must be opposed--that’s my opinion,” Ryzhkov told reporters at the annual May Day demonstration in Red Square. “If people want me and I am nominated, if the task is put that way (to oppose Yeltsin), then I am ready for the campaign.”

Half a dozen candidates are already preparing to challenge Yeltsin in the June 12 election for Russia’s new executive presidency. Yeltsin is the Soviet Union’s most popular politician in all opinion polls, and a search is apparently under way within the Communist Party leadership to find a candidate who could mount a viable challenge, yet be able to accept defeat.

In some of the harshest criticism of Yeltsin yet, Ryzhkov had described the Russian leader in a television interview in March as unfit to hold power and a danger to the country’s political and economic reforms.

“Power should not be entrusted to people like him,” Ryzhkov said. “He is not the sort of man who can use power wisely. . . . He is apt to do much harm. He has none of the qualities needed by a top leader. I think he rose to the top by chance, on the crest of a wave.”

Ryzhkov, 61, who retired as prime minister after suffering a heart attack in late December, appeared fit as he watched the May Day parade with other dignitaries beside the Lenin Mausoleum. “I was ill, but that’s over,” he said.

He said that many in the Communist Party leadership and from the country’s major industrial centers have pressed him to run against Yeltsin and that he is prepared to accept the nomination.

“I am grateful to all those people for believing in my capabilities,” Ryzhkov told the newspaper Komsomolskaya Pravda in an interview published Wednesday. “This is the highest post in the Russian republic, and therefore I consider the proposals to be very interesting.

“Moreover, as a citizen, I cannot stay aloof from active politics. . . . If such high trust is put in me and I am nominated, I am ready to enter the election campaign. As to what will come out of it, we will see. Let the people make their choice.”

Ryzhkov, a technocrat from Siberia, became prime minister in September, 1985, shortly after President Mikhail S. Gorbachev assumed the Soviet leadership. He was succeeded by Valentin S. Pavlov, his finance minister, in January during a reorganization.

A respected figure in Gorbachev’s reform effort at the outset, Ryzhkov had by last year become the target of radical reformers, notably Yeltsin and his supporters, for his insistence on a phased transition from a centrally planned to a market-dominated economy. As the criticism grew, Gorbachev and Ryzhkov became increasingly disenchanted with one another.

Ryzhkov could have the best chance against Yeltsin. They worked together in Sverdlovsk, an industrial center in the Ural Mountains, where Ryzhkov managed one of the country’s largest machinery plants and Yeltsin was a party leader. Ryzhkov’s experience at the top is unrivaled, even by Yeltsin, and his abilities as a manager were never questioned even when his economic policies were under attack by radicals. As his successor imposes new taxes, raises prices and threatens even sterner measures, Ryzhkov is remembered with some fondness.

“Yeltsin rants at rallies about party functionaries, forgetting that he comes from among them himself,” Ryzhkov said in the television interview.

Yeltsin was proposed by Democratic Russia, a coalition of liberal and radical reform groups, and a drive is under way to collect 100,000 signatures to put his name on the ballot by petition.