Soviet President Mikhail Gorbachev, under immense pressure to break the political and economic impasse in the nation, overwhelmingly won preliminary parliamentary approval Saturday for a sweeping reorganization of the executive branch of government and clear consolidation of power under the president.

Gorbachev, in another display of political agility, made his surprise proposals to the Parliament just a day after it opened an emergency session and heard calls for the resignation of the prime minister and creation of an emergency "anti-crisis" coalition government.With the single stroke, he seemed to cool the boiling rage of the day before and to wipe out the power of his unpopular prime minister, Nikolai Ryzhkov, without actually forcing his resignation.

The Supreme Soviet immediately voted 316-19 to endorse his plan "in principle," and a detailed resolution is to be considered by the Parliament by Friday. The Parliament's parent body, the Congress of People's Deputies, will convene Dec. 17 to carry out any necessary constitutional changes.

"I propose carrying out an urgent fundamental reorganization of executive power in the center by subordinating it to the president," Gorbachev told the lawmakers, opening the parliamentary session with the kind of specifics he had lacked Friday.

He described the plan as a "radical reorganization of the central executive power" making the president the clear and single head of the executive branch of government, which currently has a president and a Presidential Council, and a prime minister and Council of Ministers.

He said that he would eliminate the Presidential Council, a kind of collective decision-making body created last spring, and replace it with a Cabinet subordinate to him.

At the same time he called for strengthening the Council of Federation, a consultative body made up of the presidents of the 15 restive republics. "Anything affecting the entire country, whether decided by the center or republics, must be discussed and given the go-ahead by the Federation Council," he said in a move clearly designed to pacify republics that want to leave the union.

Gorbachev did not spell out the fate of Ryzhkov, but his reorganization seemed to leave little, if any, role for the prime minister and his Council of Ministers. Ryzhkov, prime minister throughout the more than five years of perestroika, said he learned of the proposals only 20 minutes before Gorbachev's speech. He said the new power structure also would replace the Council of Ministers. "It will be presidential rule with the Cabinet," he told reporters. He refused to say whether he would serve in the new Cabinet.

Georgi Shakhnazarov, a Gorbachev adviser, told reporters that under the proposed changes, the Soviet president and the Federation Council would possess all executive power in the country. "I think the last word will be the president's, but most, if not all, decisions will be taken on the basis of agreement" with the Federation Council, he said.

Gorbachev's proposals abruptly changed the mood of the hall where he had been under merciless fire the day before. "Today, for the first time, I see President Gorbachev," said one deputy, capturing the new hopefulness among the many deputies who have been longing for a stronger executive to take on the burden of the nation's woes.