The Philippine National Assembly formally proclaimed the reelection of President Ferdinand Marcos to a new six-year term early today after opposition legislators staged an unprecedented walkout, saying the proclamation was based on fraudulent returns.

Marcos and his running mate, Arturo Tolentino, were named winners at 12:13 a.m. (11:13 a.m. Saturday EST) after completion of the canvassing of returns by the assembly, the Batasang Pambansa.

Opposition floor leader Jose Laurel, who led the last-minute walkout, afterward condemned the proceedings as "a spurious proclamation of a spurious president."

Opposition candidate Corazon Aquino issued a statement after the assembly's tally became clear, asking, "So what?" She added, "We never doubted that he had the votes of his puppet members of the Batasan. Still, nobody believes he is president." Aquino plans to lead a "people's victory" rally at 3 p.m. today (2 a.m. Sunday EST), kicking off a campaign of nonviolent protest aimed at unseating Marcos.

The proclamation came shortly after Philip C. Habib, special envoy of President Reagan, arrived in Manila to consult with leaders on both sides about the political crisis that has grown out of the election.

The government depicted the proclamation as helping to solve the crisis by ending uncertainty as to who was the winner. But opposition legislator Marcello Fernan said this morning: "We feel that ramming this proclamation down our throats will only serve to exacerbate the situation."

The opposition said Marcos' ruling New Society Movement railroaded the proclamation partly to present Habib with a fait accompli, following repeated statements from Washington in recent days questioning the validity of the election.

After the proclamation, pro-Marcos legislators went to the Malacanang presidential palace to inform the 68-year-old president of the ruling.

Marcos told them, "Tonight we celebrate a historic victory." He said it followed "one of the most hard-fought battles of my life."

The assembly's final official tally had Marcos winning with 10,807,197 votes to Aquino's 9,291,716. Tolentino had 10,134,130, topping the 9,173,105 of Aquino's running mate, Salvador Laurel, the younger brother of the parliamentary opposition leader.

However, an independent citizens' poll-watching group known as Namfrel, which conducted its own unofficial vote count, had Aquino leading early this morning with 7,502,601 votes to Marcos' 6,787,556 with 69 percent of the precincts reporting.

Namfrel showed Laurel leading with 7,255,925 votes to Tolentino's 6,385,293.

Namfrel officials said they were only counting results from places where they had poll-watchers, because they could not vouch for the authenticity of other results. The National Assembly counted voting returns that Namfrel and the opposition consider to be fraudulently inflated in favor of Marcos.

A statement by three U.S. senators visiting Manila indicated that they had reached similar conclusions. "It is clear there was massive fraud initiated by the Marcos government to frustrate the democratic process," the statement said. "Such actions violate everything we believe as Americans. We must not, and cannot, condone this mockery of democracy by remaining silent. Millions of brave Filipinos deserve more from America."

The senators, David L. Boren (D-Okla.), Carl Levin (D-Mich.) and David H. Pryor (D-Ark.), said they were deeply impressed by a statement of Philippine Roman Catholic bishops yesterday condemning "unparalleled" election fraud.

Yesterday afternoon, the parliament finished tabulating election result documents, called certificates of canvass, from the country's 140 electoral districts. Opposition members challenged the validity of all but two of them on grounds ranging from improper sealing to nonexistent precincts.

The opposition wanted to debate these objections before a proclamation was made and present a minority report detailing what they called widespread irregularities that changed the result of the election.

But shortly before midnight, a government party member read a majority report calling for immediate proclamation and dismissing the opposition's objections as inappropriate for debate by the assembly.

When assembly speaker Nicanor Yniguez, who served as Marcos' campaign manager, rejected an opposition move to defer the proclamation, the 30 opposition legislators present stalked out in protest. Wearing yellow pins reading "Cory is my president," they flashed the opposition's laban (fight) hand signal as they left the chamber.

Within minutes, Yniguez was calling for a vote on the proclamation resolution. It passed unanimously with a roll call. When Yniguez said, "I hereby proclaim Ferdinand E. Marcos the duly elected president," loud applause from Marcos supporters in the gallery filled the chamber.

After the walkout, Marcos' labor minister, Blas Ople, took the microphone to denounce the opposition for what he called "a disgusting spectacle in these august halls."

Opposition legislator Luis Villafuerte said, "This is the first time in the history of the Philippines that the president and the vice president have been proclaimed without the participation of both parties."

In a news conference after the walkout, opposition leaders said they had been double-crossed by Marcos' party, which they said had promised that the session would not vote on the proclamation until next week, after the minority report was presented.

They charged that speaker Yniguez's 45-page majority report had been prepared by Marcos' palace staff and that the hasty proclamation had been ordered by Marcos.

Besides enabling Marcos to deal with envoy Habib as a newly proclaimed president, the quick move was said by the opposition to be intended to preempt Aquino's rally this afternoon and to defuse tensions over the election.

Opposition legislators said they would join a civil disobedience campaign that Aquino is expected to launch at the rally and would consult with their constituents as to whether they should remain in the assembly.

Parliamentary opposition leader Laurel said in a statement that Marcos' party "has already made a mockery of the past election, which was the dirtiest, most dishonest and bloodiest election in the history of this country." He added, referring to the proclamation: "This, the people can never respect or obey."

The opposition claimed that without "massive vote-buying and widespread terrorism used upon the citizens" by Marcos' party, Aquino would have gained 2.5 million votes, assuring her victory.

In his 2:30 a.m. remarks to supporters after being notified of the proclamation, Marcos said: "As one who's been in many a battle -- both political and physical -- I can tell you that this was one of the most hard-fought battles in my life." He said the just-concluded campaign would become "legend" and that historians would praise his new administration as having "worked to protect and save the democracy of our republic."

There was no immediate word from the palace on when Marcos would meet U.S. envoy Habib, who arrived here last night on a U.S. government plane and was whisked off in a limousine. Habib made no remarks to reporters. There has been speculation here that he may try to broker a deal for reconciliation between Marcos and Aquino.

Last night, Labor Minister Ople said that if that is his goal, "Mr. Habib has set himself a task tougher than any he has pursued in the past. We all wish him luck. We assume he comes with a lot of good faith."

Ople said the Philippine government "would take the greatest offense" if Habib proposed any plan calling for Marcos to step down.

Rene Saguisag, an opposition spokesman, told reporters today that Aquino is willing to meet Habib to assist in fact-finding but not to negotiate any deal. Habib also is expected to meet with Marcos and church, government and private sector representatives.

Meanwhile, the three U.S. senators, who arrived here Friday night, said in a statement after a day of meeting with various officials: "We will urge our government to avoid any action which would give legitimacy to the Philippine government's official returns."

Boren, the group's leader, later said that "if we make serious mistakes of policy now, we could set the stage for ultimate victory by radical elements of the Philippines."

"If we do not do everything possible to encourage President Marcos to voluntarily step down, it will damage the course of U.S.-Philippines relations for years to come. Especially the young people who trust America to stand for democratic ideals will feel betrayed."

In another development, Marcos said he had ordered Lt. Gen. Fidel Ramos, head of the Philippine Constabulary, to meet with opposition officials to discuss ways to avoid conflict between pro-Aquino demonstrators and government forces.

Marcos said in an interview with CBS News yesterday that he would follow a policy of "maximum tolerance" toward opposition protests.

In continuing election-related violence, the Aquino campaign reported that six more campaign workers were tortured and slain during election week. They included three women who appeared to have been raped and whose mutilated bodies were found in Quirino Province, the campaign reported. Two had been beheaded.