Conservative leaders said yesterday that Tuesday's Supreme Court decision reaffirming a ban on state-sponsored prayer in public schools has provided the spark of anger they need to launch new drives for a constitutional amendment and legislation to permit prayer in public schools.

Sen. Orrin G. Hatch (R-Utah) said he will hold hearings as early as possible next week on a school prayer amendment. "The tragedy of this opinion," he said, "is that it transforms neutrality toward religion into hostility toward religion."

Sen. Jesse Helms (R-N.C.) denounced the ruling as an "unwise and unjust decision, delivering a slap in the face to the vast majority of Americans who favor school prayer . . . . "

Helms said that while he supports the goal of Hatch's constitutional amendment, he will renew his effort to achieve the same result through legislation instead.

"It's time for Congress to stand up to the Supreme Court and to withdraw federal jurisdiction over school prayer. This is a matter that clearly should be left to the states, which is where it was until the 1960s when the Supreme Court first began its intrusion on this issue."

He called for a Senate vote as soon as possible on a bill he introduced last January that would leave it up to the states to decide whether to allow school prayer.

Tuesday's decision is "ludicrous," said Cal Thomas, spokesman for the Moral Majority, predicting that the religious right would make a "unified push on all fronts" to overturn it.

The whole issue likely would have "just gone away," he said, if not for this ruling. "There hasn't been any push for an amendment since the court was perceived as loosening up on the issue."

The school prayer question has become a flash point for one of the touchiest and most fundamental national issues -- how to maintain the constitutional prohibition on any law "respecting the establishment of religion" without inhibiting peoples' constitutional right to exercise their religion freely.

In its 6-to-3 decision, the court struck down an Alabama law that required a moment of silence each day for prayer or meditation. The court indicated that "moment of silence" statutes in 24 other states might pass constitutional muster as long as they were not motivated by the state's expressed desire to promote religion in the classroom, as was the case in Alabama.

The ruling represented a return by the court to a stricter focus on separation of church and state, following a series of more relaxed decisions, such as one last year that upheld the right of a city to display a nativity scene.

The Reagan White House, which favors prayer in schools, declined to comment on the ruling. "We haven't had the opportunity to review it," said spokesman Larry Speakes. "We don't generally comment on Supreme Court decisions unless they're outrageous."

Repeatedly in the last two decades, school prayer advocates have worked hard to push a constitutional amendment or legislation through Congress, only to fall short.

Senator Strom Thurmond (R-S.C.) and Rep. Thomas N. Kindness (R-Ohio) joined the call yesterday for a renewed push for a constitutional amendment.

Sen. Jeremiah Denton (R-Ala.) said the court ruling "respresents a continuation of a distorted rationale that equates the opportunity to pray with the establishment of a state religion."

But James McClellan, director of the Center for Judicial Studies and a longtime advocate of prayer in schools, said the ruling is in a way "actually a tremendous victory for us" and could open the way for court victories.

The court removed much of the doubt concerning the statutes in the other 24 states, according to McClellan. He said his cause is also helped because the majority opinion is "a complete failure" because it does not come to grips with the underlying issue of whether the Constitution prevents the states from promoting religion.

Justice William H. Rehnquist's dissent does address that question and represents the first time since 1947 that a member of the high court has challenged the established interpretation, which holds that there is such a prohibition, McClellan said.

"That cat is out of the bag and the pro-prayer groups now have a rallying point they did not have before," he said, calling the dissent an "opening wedge" for future court cases "to overturn 40 years of interpretation."