The influential archbishop of San Salvador said today that his church would "gladly" cooperate with a proposed government amnesty program for leftist guerrillas. In his opinion, he added, the rebels do not have the support of the people.

Archbishop Arturo Rivera y Damas' remarks came as the U.S.-backed government was preparing to unveil a proposed general amnesty, a copy of which this reporter obtained today. It provides for the pardon not only of guerrillas but also of most political prisoners.

The success or failure of the program is expected to be a major element in the effectiveness of elections scheduled for December as part of a political solution to the intensifying civil war here.

The guerrillas and their political allies already have rejected either an amnesty or an election and insist that the only means to achieve peace is through unconditional dialogue with the government.

Rivera y Damas has been a key advocate of negotiations and he said this morning that he would continue to favor talks as a means of achieving peace. But he was critical of the guerrillas, suggesting they may have sabotaged their own initiatives, while he tended to endorse the government's latest position.

Rivera y Damas presented his views partly in the context of Pope John Paul II's visit here this month. The pontiff called for dialogue but cautioned about the dangers of negotiating with ideologues.

Since then, the archbishop said, "I note a greater opening to search for new ways toward a solution. There is calm. There is optimism. There is a desire for understanding more than revenge." Asked if that judgment would apply to both sides in the conflict, Rivera y Damas replied, "I would say at least on the side of the citizenry in general and of some elements of the government."

Continuing with that theme later in the interview, the archbishop said, "The population wants there to be peace. I do not see that the guerrillas, who have progressed militarily and in experience, have popular support.

"If they did, in three years one would have seen more results. There have been about four or five offensives and who knows how many more to come. But the people want this peace ."

A copy of the proposed amnesty law, submitted yesterday to Provisional President Alvaro Magana by the Peace Commission he appointed Feb. 28, shows it would except from pardon those prisoners accused of murder, rape, kidnaping and "terrorist acts" that caused "grave wounds or mutilations in the civil population."

The program conspicuously omits any active role for the military. Instead, a three-member committee, including representatives of the Peace Commission, the government Human Rights Commission and the Interior Ministry would administer the amnesty. The Interior Ministry does not have police functions but handles civil administration of municipalities.

Guerrillas accepting the amnesty would come under the care of a "rehabilitation committee" responsible for "the measures that are urgent and necessary to guarantee the life, health, sustenance and labor of those favored by the law."

The plan calls for preferential bank loans for building houses, buying seed, special education programs, food, clothing, medical and other assistance. Those wishing to take advantage are to have 40 days to do so after an as-yet unspecified starting date. The Constituent Assembly, which must approve the proposal, apparently would set the date.

The proposal does not say where rebels who might want to surrender can safely do so. Such details remain to be worked out. In a brief interview with ABC News yesterday, Magana suggested churches as potential receiving points.

Rivera y Damas said the canonical law that gives church property the status of asylum would have to be recognized by the government. "Then, if we can give that service, we will gladly do so."

Rivera y Damas seemed particularly enthusiastic about the earlier reported inclusion of political prisoners under the proposed law.

The archbishop said that the presence of the bishop of Santa Ana, Rene Revelo, on the Peace Commission is "a guarantee of its efficacy." He emphasized that it should not be a "bureaucratic organism" but should "accomplish a mission of effectively pacifying the country."

In October, Rivera y Damas and Revelo delivered the guerrilla front's initial negotiating position to Magana. The government subsequently appeared to rule out a dialogue.

Rivera y Damas described the rebels' increase in violence beginning in October as having "something of the flavor of blackmail."

"But I won't enter into judging in the thing," Rivera y Damas said. "The difficulty was that of the other interlocutor in giving reponse at that moment."

Asked if the government would be disposed to talk if there were new signs of good will, the archbishop said, "I have that impression, that if there are signs of good will they would be taken advantage of on the part of the government and also vice versa."