There is still hope - although only faint hope - for an accord of some sort between Nicaragua's Sandinista rulers and the political opposition, sources close to both sides say.
Nicaraguan junta coordinator Daniel Ortega Saavedra and other Sandinista leaders publicly say they will not give in to the opposition demand for a postponement in the election, now planned for Nov. 4.
But well-placed observers close to both sides say privately that it is still possible that some sort of agreement will be reached. Some say chances for an accord on postponing the vote and other disputed issues are ''50-50.'' Others give it only a ''20 percent chance.'' But no one rules it out.
The main opportunity to reach an accord may come at this week's Socialist International conference in Brazil, which top-level Sandinista and Nicaragua opposition figures are attending.
One problem both sides must surmount is their widely differing positions on when to hold the election. The Sandinistas have set the election for Nov. 4 and the date for registering presidential candidates at Sept. 30. With the registration date already passed, any changes will be politically difficult for the Sandinistas.
Many on the more conservative side of the Sandinista leadership do not want to budge on these dates, but the more moderate and liberal Sandinistas want to allow the chief opposition candidate, Arturo Cruz Porras, to participate in the election. The moderates believe that if Mr. Cruz has a role in the vote, the international community will view the Nicaraguan electoral process as legitimate.
Another basic problem is that although Cruz wants to reach agreement and participate in the election, he must satisfy his own right wing, which prefers not to take part.
Sandinista suspicions were heightened when the ''Coordinadora'' (a coalition of opposition parties) took roughly two weeks to answer informal (and, according to the opposition, rather unclear) Sandinista proposals that the election be postponed for one month.
When the opposition finally did answer - last Friday - its response, although flexible on many points, contained two hard-line demands that were unacceptable to the Sandindistas. These positions were (1) postponement of elections until Feb. 23, and (2) a Sandinsita condemnation of Soviet and Cuban intervention in Nicaraguan affairs.
Many viewed the opposition's response as bones that Cruz was throwing to the right wing, and that he himself did not intend to stand by. By the end of the weekend, Cruz sent word to the Nicaraguans that he was flexible on the date of the election and that, instead of condemning Soviet and Cuban intervention, it would be acceptable for the Sandinistas to condemn all foreign intervention.
Cruz says he would not participate in the elections unless the Sandinistas guarantee their fairness. He also demands: (1) international supervision of the vote; (2) guarantees that the Sandinistas will respect election results, whoever wins; (3) complete freedom of mobility for the opposition parties, including protection of opposition candidates from mob attacks; (4) freedom of the press. He continues to refuse to register as a candidate unless the Sandinistas comply with these conditions.
The Sandinistas are under international pressure to make the election visibly free and fair. According to Sandinista sources, the concessions that the Sandinista National Liberation Front wants from Cruz revolve around what they describe as ''Cruz's publicly disassociating himself from Reagan's view of the world and of Central America.'' They wish Cruz to distance himself from United States support rebel contras who are fighting the Sandinista government, and from the US military presence in Honduras.
Specifically, they want Cruz to reaffirm his support of the points in the Contadora draft peace plan that deal with arms limitation and the reduction and eventual ban on foreign military advisers from Central America, including the US presence in Honduras. The Sandinista government accepted the draft peace plan 11 /2 weeks ago.
The role of middlemen - such as Colombian President Belisario Betancur - has been important in this process. Mr. Betancur has relayed messages between the opposing sides and pressed them to compromise. Also involved have been the Venezuelans and Mexicans, with European Social Democratic leaders such as Spanish Prime Minister Filipe Gonzalez also becoming active.
Democratic observers in Congress maintain that despite declarations to the contrary, the Reagan administration does not, on the whole, want to see an arrangement worked out between the Sandinistas and Cruz, and would prefer to continue pursuing a hard-line policy. They do, however, acknowledge that the State Department and US Secretary of State George Shultz have moderated their position.
Pressure from middlemen has helped to produce compromises on both sides, with Cruz first dropping a demand that the Sandinistas negotiate with all of the opposition, including the Hondoran-based rebel contras, and then dropping his demand for formal talks between the Sandinistas and the opposition.
Those in the Nicaraguan opposition who still believe compromise is possible place most of their hope in strong international pressure - and point out that, if the Sandinistas refuse to compromise, they may completely alienate their noncommunist national supporters.
Some US Democrats believe the Sandinistas are caught up in an internal struggle over whether to postpone elections. They also stress the importance of outside pressure being exerted by Colombian President Betancur and Social International members in Brazil.
Those still hoping for a compromise point to several opportunities: this week when Daniel Ortega is in New York addressing the United Nations and Sandinista leaders and the opposition are in Brazil, and Oct. 13 when West German Social Democratic leader and former prime minister Willy Brandt visits Nicaragua.