Confident of defeating President Reagan's request for military aid to antigovernment rebels in Nicaragua, Democrats yesterday drafted several proposals to provide humanitarian aid instead, including one that House Speaker Thomas P. (Tip) O'Neill Jr. (D-Mass.) said would allow the Red Cross to distribute the funds to "worthy people."

In an apparent effort to stave off defeat, the president told a late afternoon meeting of legislators that he "might be willing to compromise on the timing" of his proposal, but on no other aspect, a senior administration official said.

Reagan continued to campaign hard for his plan, stating when questioned during a photo session with Algerian President Chadli Bendjedid that Pope John Paul II "has been most supportive of all our activities in Central America." Asked if that included military aid, Reagan said, "I'm not going into detail, but all our activities."

The pope's ambassador to the United States, Archbishop Pio Laghi, said the pope did not support military aid, however.

"If the Holy Father recognized a willingness for an opening of dialogue that could lead to peace in Central America, it would have to be interpreted in accord with the constant position of the Holy See, expressed by the pope himself on numerous occasions, and we, therefore, exclude the possibility of his support or endorsement of any concrete plan dealing, in particular, with military aspects," Laghi said.

White House spokesman Larry Speakes also backed away from the remark, saying Reagan's statement did not imply Vatican endorsement. "I don't think the Holy Father is in the practice of getting that involved in U.S. policy," he said.

Several members of Congress warned Reagan at White House meetings that he faces a decisive repudiation when Congress votes Tuesday on his request, which would release $14 million to the rebels through the Central Intelligence Agency. Reagan has said he would use the funds for food, clothing and medicine during a cease-fire and would spend it for arms only if the rebels and the leftist Sandinista government of Nicaragua do not make progress by June 1 in negotiation toward elections.

A senior administration official said Reagan recognized "a genuine desire to be supportive" on the part of several Democratic members who visited him and had decided to consider extending the June 1 deadline. "The president is not willing to compromise on policy and not on dollars, but perhaps on timing," the official said. He added, however, that "there is a lot to be done before we have language on a bipartisan agreement."

O'Neill said the Democratic alternative, still being worked out, would be offered after an up-or-down vote on the president's proposal and would be designed to encourage regional peace negotiations and forestall greater U.S. involvement in actions against Nicaragua.

"I don't believe the president of the United States will be happy until troops are in there," O'Neill said. "I want to do everything in my power to prevent that."

Lawmakers and others familiar with the proposal, which is being written by Permanent Select Committee on Intelligence Chairman Lee H. Hamilton (D-Ind.) and Rep. Michael D. Barnes (D-Md.), said it would provide $3 million to the Red Cross for refugee and humanitarian assistance and $11 million to the so-called Contadora regional peace process organized by Colombia, Venezuela, Panama and Mexico.

The $11 million would help those countries monitor the peace process and implement any peace treaty between Nicaragua's leftist government and the rebels, known as "contras," officials said.

Several other proposals also have been circulated, but officials said none appeared to have as much support as the Red Cross-Contadora idea at this point.

One would provide about $3 million in humanitarian aid to rebel families now and offer another $3 million in a few months provided some progress is made in negotiations with the Sandinistas. Rep. James R. Jones (D-Okla.) drafted another that he called "a middle ground . . . to bring about a cease-fire and bring the parties to the peace table."

He said it would restrict the $14 million to food and medical services for 90 days while peace talks began, allowing military aid to resume thereafter only if Congress agreed. The proposal also would spell out goals for the government of Nicaragua -- such as freedom of the press and movement toward democratic procedures and political pluralism -- that, if met, would lead to the resumption of U.S. trade credits and other benefits for Nicaragua.

In the Senate, Foreign Relations Committee Chairman Richard G. Lugar (R-Ind.) and Select Committee on Intelligence Chairman David F. Durenberger (R-Minn.) were reported to be composing a resolution that would avoid a vote by ending military aid but declaring Congress' firm support for the contras.

Another proposal, made in a speech to the Coalition for a Democratic Majority last night by Sen. Sam Nunn (D-Ga.), would suspend U.S. military maneuvers in Honduras if the Sandinistas agree to a cease-fire, peace negotiations and an end to their official state of emergency that has suspended legal rights to due process. The rebels would receive humanitarian aid and be called upon to purge their ranks of people guilty of human rights abuses. Military action would remain an option, he said.

Nunn said he was sure that Reagan's proposal would lose in the Senate, but said, "even if he wins, I believe he will simply be postponing for a few months the inevitable termination of all aid to the contras."

Republicans in the House said yesterday that they have all but given up hope of winning the vote. "We're stalled at this point," one GOP official said. The senior administration official said Democratic leaders had rejected GOP members' requests for a new rule on floor procedure that would allow them to modify Reagan's proposal and thus avert a showdown. Its language was prescribed in a law passed in October.

House Republican leader Robert H. Michel (R-Ill.) said that Reagan remains "a hard bargainer and negotiator, but I think it is time for those of us with a responsibility for carrying water to see what can be done in the way of adjustment."

The administration appeared to suffer another rebuff in a letter to Reagan from Colombian President Belisario Betancur spelling out his opposition to the military side of Reagan's plan. "Your initiative that supports a cease-fire and backs the opening of talks between the Nicaraguan government and groups of the democratic opposition is positive and constructive," he wrote, "but military aid to the groups opposed to the Nicaraguan government worries me."

Meanwhile, Reagan's national security affairs adviser, Robert C. McFarlane, told a Capitol Hill conference of the conservative Citizens for America that, if Congress approves Reagan's plan, the funding "has to be sustained in successive votes to come," but "what funding it will involve cannot be predicted."

He declined to confirm or deny a report in The New York Times that a top secret document submitted to Congress said the administration plans to expand the rebel force to 20,000 or 25,000 men and will consider direct U.S. intervention as a last resort.

However, Adolfo Calero, leader of the largest rebel group, the Nicaraguan Democratic Force, told the same conference his troops could "provoke a turning point" of popular uprising in Nicaragua and a split in the Sandinista forces if they received $30 million to $50 million at one time. This would allow him to arm 20,000 more troops, he said.

At a meeting of the administration's weekly "Central America Outreach" program, British Conservative Party member John Browne said Soviet interest in Nicaragua is part of an attack on NATO as well as the United States. He, said new Soviet leader Mikhail Gorbachev and his wife are so attractive they "have the capability of developing into a team like President and Mrs. [John F.] Kennedy . . . which will result in a stronger Soviet Union."