A massive mail and telephone campaign by conservatives against the nomination of Paul C. Warnke to head the U.S. arms control team flooded Senate offices as the Senate decided yesterday to vote on Warnke next Wednesday.

Republicans opposing Warnke's nomination to head the Arms-Control and Disarmament Agency and lead the U.S. team in strategic arms negotiations with the Soviets abandoned their threat of a filibuster in return for a debate that will begin today and run until the vote late Wednesday.

The decision, worked out by the Senate leadership, appeared to ensure Warnke's confirmation to both posts, but conservattive spokesmen said the opposition to Warnke should signal President Carter that there is widespread public concern about the administration's national security policies.

"I think youre going to see a tremendous effort by the conservative community to oppose Mr. Carter on national security issues," Richard A. Viguerie said yesterday.

Viguerie's direct mail business has sent out more than half the roughly one million pieces of mail aimed at stirring public opinion to Warnke. The letter asks the recipients to sign an enclosed card and send it to a senator.

Viguerie is a member of the steering committee of the Emergency Coalition Against Unilateral Disarmament which was formed to fight the two nominations and did the direct mail for another conservative group, the Committee for the Survival of a Free Congress.

Warnke supporters in the Senate and the administration believe there are still fewer than 30 Senate votes against him.

Morton Blackwell, executive director of the coalition and a Viguerie associate, said yesterday there are 31 definite votes against Warnke as chief strategic arms negotiator.

"They haven't got a chance of getting two-thirds," Blackwell said.

Townsend Hoopes, former under secretary of the Air Force who has been loyying for Warnke, said Warnke supporters were disturbed by the increasing volume of mail produced by the conservative groups. "The initiative has passed to the other side," Hoopes said.

President Carter is expected to speak out to staunch any hemorrhage of support during his Saturday afternoon radio talk the show.

In addition, Secretary of State Cyrus R. Vance and other administration officials were being approached about making statements backing Warnke, Hoopes said.

While conceding that Warnke would almost certainly be confirmed, Viguerie said: "This is just the beginning. Our allies are going to include a lot of the centrist Democrats. We're going to be going with the tide."

Viguerie, who has long been active in conservative politics and fund-raising, said that national security issues would be his major concern in the months to come and that "Democrats have been shocked by how far Carter has gone to the left on national security."

The American Conservative Union and the American Security Council have been working in the anti-Warnke drive, but Viguerie clearly hopes for a widening coalition against Carter's national security policies that will include many not normally close to the conservative camp.

A random survey of Senate offices yesterday showed large numbers of anti-Warnke postcards being received, in some offices 500 or more a day.

To register opposition to Warnke, a citizen only has to fill in his or her senator's name and sign the card.

Receptionists in several Senate offices reported getting telephone calls opposing Warnek from Orange and Marin counties in California. The callers express their views and then ask to be transferred to another Senate office. The offices of Sens. S. I. Hayakawa (R-Calif.), Dennis DeConcini (D-Ariz.), lee Metcalf (D-Mont.) and John Melcher (D-Mont.) were receiving such calls.

An administration supporter of Warnke acknowledged that his forces are in "an uncomfortable position" by having to wait until Wednesday for the vote.

"We would have like to see the vote yesterday or last week," he said. "Delay will work against us."

However, administration officials were pleased to have a date for the vote and the threat of a filibuster dropped.

The Senate will first probably consider a move to recommit, and thereby kill, the two nominations. if that fails, as GOP whip Ted Stevens (Alaska) conceded it probably will, the Senate will vote separately on each nomination beginning about 5 p.m.

Majority Leader Robert C. Byrd (D-W. Va.), who worked out the agreement with Republican leaders, gave the Warnke forces some encouragement by saying he found Warnke's testimony before the Foreign Relations Committee "ver satisfactory."

Byrd said, however, he is still undecided.