President Boris Yeltsin's political rivals denounced his proposed constitution Friday as an attempt to establish authoritarian rule and warned him against trying to adopt it behind their backs.

Plans to adopt a new constitution are tangled in the ongoing power struggle between Yeltsin and the Congress of People's Deputies, a stronghold of his hard-line opponents.Yeltsin's draft constitution would replace the Congress with a new bicameral legislature and give the president sweeping powers, including the right to dissolve parliament, to appoint his entire Cabinet and to introduce a state of emergency.

Yeltsin said he wants the new constitution to be approved by the Federation Council, a body consisting of Russia's regional leaders. The draft has already been sent to them for consideration, and they are to present their judgment by May 20.

Yeltsin's chief rival, parliament speaker Ruslan Khasbulatov, warned him against attempts to bypass the Congress. "It's unthinkable to pass the new constitution by unconstitutional means," he said.

In his first major speech since winning last month's referendum on his leadership, Yeltsin said Thursday that Khasbulatov's decision to convene the constitutional commission Friday was unlawful.

"The president of Russia is the chairman of the constitutional commission and I will take the decision to convene the constitutional commission when the necessity arises," he said.

The commission was formed by the Congress, which appointed Yeltsin chairman of the body. The commission's mission was to replace the existing Soviet-era constitution.

Oleg Rumyantsev, the commission secretary who was the main author of a proposed constitution written last year, said Friday's session was legal since Yeltsin had asked the commission to consider his draft.

"The draft puts the president above all branches of power, which is characteristic for authoritarian rule and far from democracy. Even Latin America rejected such regimes 40-50 years ago," Rum-yant-sev said.

The commission, however, carefully worded its final decision, apparently to avoid a direct clash with Yeltsin, stating that his draft "curbs political, economic and civil rights of citizens of Russia" and asking the president to cooperate with the commission.