MANAGUA, NICARAGUA, NOV. 9 -- Interior Minister Tomas Borge, in a speech late yesterday that sought to dispel rumors of internal tensions in the highest Sandinista ranks, denied there are rifts over a move to open an indirect cease-fire dialogue with the U.S.-backed rebels.

"We will never be divided," Borge proclaimed to about 400 members of the Sandinista National Liberation Front. Borge is the eldest of the nine commanders of the National Directorate that controls the ruling Sandinista party.

A feud in the front is "our enemy's most persistent dream, in cinemascope and technicolor," said Borge, the only surviving founder of the one-time Sandinista guerrilla army. It celebrated its 26th anniversary yesterday with his speech.

Borge's statement followed lukewarm reaction from Sandinista grass roots and media organizations to the Nov. 5 announcement by President Daniel Ortega of the proposed cease-fire negotiation with the rebels, known as contras.

On Friday, Ortega asked Cardinal Miguel Obando y Bravo, the most influential critic within Nicaragua of the Sandinistas, to serve as intermediary. Obando said after mass yesterday that he will give his answer late this week. He is expected to accept, providing certain conditions are met.

Pro-Sandinista Nicaraguans were anxious to hear Borge because, as the minister in charge of jails, intelligence and the state security police, he has led the political side of the Sandinistas' six-year war with the contras.

"When we took this position," Borge said, "we knew some would see it as a step backwards for the revolution. We knew it might even cause confusion. But this is a step forward." He implied that the decision was taken jointly by the top Sandinista leaders at the time of the Aug. 7 Central American summit meeting that resulted in a regional peace plan that took effect Thursday.

The Sandinistas' most passionate Marxist and rousing speechmaker, Borge has sometimes appeared out of step with the unfolding peace process. For example, he confessed to Nicaraguan editors that he learned of the Sept. 19 decision to reopen the opposition daily La Prensa from his car radio as he was driving to work the next morning.

But Borge denied there is any conflict between the government's call for indirect dialogue with the contras about a cease-fire and an Oct. 29 Sandinista party statement that said there would never be a "political dialogue" with them.

Obando had questioned at the time whether that statement was merely a party position or government policy. The issue started to clarify Thursday as the Sandinistas said they see arms-length cease-fire exchanges and a "political dialogue" as two very different matters.

Last night, Borge reaffirmed the party text and said negotiations over anything but the cease-fire would be an attempt to "question an unquestionable power," that is, Sandinista rule.

According to Borge, the only broad political dialogue the government will accept will be one already haltingly under way with a number of opposition political parties. The peace accord calls on governments to "arrange" cease-fires, but does not mandate talks with armed rebels.

Contra leaders have differed in recent days in outlining their expectations. In San Jose, Costa Rica, Alfredo Cesar, a director of the Nicaraguan Resistance, the contra alliance, said by telephone that the contras never sought to discuss anything more than a cease-fire. He added, however, that they hope to turn the indirect dialogue into face-to-face talks.

Speaking to journalists in Miami over the weekend, conservative Nicaraguan Resistance leader Adolfo Calero said the dialogue cannot succeed without a broader political agenda.

{In San Jose, Costa Rican President Oscar Arias, the principal sponsor of the August peace plan, said Monday night, "The peace process is going one step at a time .. . . Now it is easier to see a bilateral dialogue between Washington and Managua. I would not rule out the possibility of a direct dialogue between the two," Reuter reported.}

Meanwhile, in his homily, Obando gave a cautiously positive report on the government's stance. Listing the reopening of opposition media and the creation of a National Reconciliation Commission he heads, the Roman Catholic leader said, "I try to be honest, and I have to recognize that steps have been taken, facts which we can't deny."

Obando had critical words for the opposition parties, calling on them to stop internecine squabbling. A faction of the centrist Social Christian Party, once the largest opposition party, seized its Managua headquarters yesterday in a power struggle between two of its leaders.

A unilateral cease-fire, which was in effect since Oct. 7 in three small rural zones, was suspended Saturday. Ortega said only about 600 contras used the zones to accept an amnesty and lay down their arms. In the northern town of Quilali, on the edge of one zone, a deafening volley of Sandinista Army rifles was reported at the opening of a military offensive.