Boris N. Yeltsin said Friday in a triumphant speech to factory workers that last weekend's referendum was a vote of confidence in his Russian leadership even though it "broke all records for ambiguity."

Voters on Sunday overwhelmingly approved Yeltsin's proposal to create a popularly elected presidency in Russia, the largest and most populous of the 15 Soviet republics, as well as Soviet President Mikhail S. Gorbachev's commitment to a renewed federation.While Gorbachev has yet to comment on the results of the referendum, Yeltsin in his first public statements on the vote claimed victory.

"We see the results of the Russian and union referendums as an expression of support for the Supreme Soviet and the leadership of Russia," he told workers at the huge Kirov tractor factory in Leningrad.

Approval of his proposal for an executive presidency in Russia, by 75 percent of the voters, is powerful ammunition for Yeltsin as he heads into a congress of lawmakers from Russia starting Thursday. A group of hard-line Communists plans to propose a motion of no-confidence in Yeltsin, who has been head of the republic since May.

He is commonly referred to as president now although his formal title is chairman of the Supreme Soviet, the Russian federation's legislature. He was elected chairman by fellow lawmakers, not the public.

Yeltsin told the factory workers he will run for president in a plebiscite whose date has not been set.

While the Communists are trying to dump Yeltsin, he has been leading a campaign to remove Gorbachev, his one-time patron in the Soviet leadership. Yeltsin won a standing ovation at the Kirov plant's auditorium when he repeated his demand for Gorbachev's resignation.

"Resign! Resign!" Yeltsin led the audience in chanting.

Yeltsin repeated accusations that Gorbachev has turned from a reformer into a conservative.

"At the head, unfortunately, of the rightist-conservative wing is the president himself," Yeltsin said.

He blamed Gorbachev for failing to draft a comprehensive program to fix the country's economic ills, citing price increases on a wide range of goods scheduled to take effect April 2.

"What did they start with? A raise of prices. That's their economic program: to begin immediately by putting a maximum load on the people's shoulders."

He promised to present a Russian program for economic reform to the republic's Congress session starting next week.

Yeltsin said he supported the principle behind the referendum on preserving the Soviet Union, even though the question on the ballot "broke all records for ambiguity, its tactless formulation and lack of clarity."

Critics have said too many issues were packed into the question, so voters could not register separate views on whether republics should be socialist, sovereign or whether there should be a union at all.

Yeltsin said people who voted "yes" - about 77 percent - did not want to preserve "the old union."