Protestant and Jewish religious leaders are campaigning against what they foresee as a Senate attempt to breach the wall separating church and state on behalf of school prayers.

Sen. Jesse Helms (R-N.C.) wants to remove from the purview of the federal courts any litigation arising out of state laws concerning "voluntary prayer" in public schools or other public buildings.

His legislation would in effect enable state legislature to suspend the 1962 and 1963 Supreme Court decisions that outlawed prayer and other devotional exercises in pulbic schools.

Helms will offer his proposal as an amendment to a bill by Sen. Dennis DeConcini (D-Ariz.) designed to give the Supreme Court greater discretion in selecting the cases it will review. The bill is expected to be called up this week.

An ad hoc coalition of religious groups has been pounding on senators' doors, mobilizing opposition to the Helms amendment.

"We believe that the responsibility for religious education rests in religious institutions and in the home, but certainly not in secular public schools," the coalition said in a letter hand-delivered to every senator.The letter is signed by representatives of the Lutheran Council. American Jewish Congress. United Church of Christ. United Prebysterian Church. Church of the Brethren. United Methodist Church and Unitarian Universalist Association.

A separate, and stronger, letter from the Baptist Joint Committee on Public Affairs expressed "unalterable opposition to any efforts to circumvent or circumscribe" the Supreme Court decisions. "Any such efforts we view as an abridgment of the First Amendment and in no way as aid to religion or the religious exercise of prayer," said the Baptist letter

Dr. James E. Wood Jr., who heads the Baptist committee, said relligious church leaders agreed that a separate Baptist statement "would be helpful, since Sen. Helms is a Baptist; in fact he often says he speaks for the Baptists."

The Roman Catholic hierarchy, which supported the Supreme Court decisions outlawing public school prayers at the time, reversed its position in 1973, calling for a constitutional amendment authorizing public school prayers. The matter, however, is near the bottom of the list of the church's priorities.

Sens. Edward M. Kennedy (D. Mass), Charles C. Mathias (R-Md.) and Birch Bayh (D-Ind.) are expected to lead the opposition to the Helms amendment.

Politically, the school prayer issue is tricky. The substantial public outrage, generally from conservative Christians, which erupted 15 years ago after the Supreme Court decisions, is largely spent. But there remain dedicated cohorts searching for sympathetic legislators willing to attempt end runs around the court rulings.

Several states, for instance, have enacted laws calling for daily periods of "meditation" in public schools. Kentucky recently passed a law requiring that the Ten Commandments be posted in every public school classrorom.