Sandinista-Catholic relations fraying

Nicaragua's expulsion of 10 foreign priests on July 9 underscores growing tensions between the Sandinista government and the Roman Catholic Church hierarchy.

The priests (four Spaniards, two Italians, two Costa Ricans, one Panamanian, and a Canadian) were expelled, Nicaragua's Interior Ministry says, for ''having violated the laws of our country, carrying out strong political activities against the . . . government, and participating in plans destined to provoke a clash between the Catholic Church and the Sandinista revolution.''

The specific ''clash'' the priests are accused of helping to provoke was a demonstration in Managua July 9. The march, headed by the Catholic archbishop of Managua, was held in support of a Nicaraguan priest accused of participating in ''counterrevolutionary'' CIA-sponsored activities. The priest, the Rev. Luis Amado Pena, is accused of gun-running to an ''internal front'' of people within Nicaragua and helping the contra guerrillas who are fighting the Sandinistas on the country's northern and southern borders.

The demonstration, which started at a Managua church and ended a few miles away at a seminary where the priest was living more or less under house arrest, involved between 200 and 300 demonstrators, according to Western diplomats. One diplomat who observed the march said, only half in jest, that there were more journalists than demonstrators.

Last month the Nicaraguan Interior Ministry staged an elaborate, highly publicized presentation of the case against Pena. It included a videotape that showed Pena speaking to a member of the contras who was reading the priest a letter from contra higher-ups congratulating Pena on his activities and thanking him for his aid.

Western diplomats are not certain that the videotape is authentic. They say it may be real, but that the possibility that it is a fake cannot be ruled out.

The march has received heavy foreign news media coverage - not so much because of its intrinsic importance but because it occurred at a time of growing tension between the church and the Nicaraguan government.

Archbishop Miguel Obando y Bravo and many of his bishops have been privately critical of the Sandinista leaders since late 1979, a few months after the Sandinista revolution. In the last year or so, this opposition has become increasingly public.

The conflict came to a head when a pastoral letter signed by the archbishop was read from the pulpits of Nicaraguan churches last Easter Sunday. The letter called for a national reconciliation and asked the Sandinistas to open a dialogue with opposition leaders, including those associated with the counterrevolution.

Interior Minister Tomas Borge and other Sandinista leaders bitterly denounced the letter. Borge has led the move for a harder line against the church hierarchy.

As open opposition to the government has grown among the church hierarchy, the Sandinistas have encouraged the development of an informal ''alternate'' church with priests more sympathetic to the revolution.

One leader of a left-wing party allied with the Sandinistas stated his opinion that Daniel and Humberto Ortega, who serve with Borge on the Sandinista directorate, are letting Borge take the lead against the church in the hope that this will undermine the interior minister's popularity among Nicaraguans. The Ortega brothers and Borge are widely considered here to be rivals for power among the Sandinistas.

''The Ortegas are giving Borge rope to hang himself with,'' says the left-wing political leader.

The Catholic faith is very strongly embedded among the Nicaraguan people. Since the revolution, diplomatic observers here have said that one factor that would make political radicalization in Nicaragua more difficult than in Cuba is that Nicaraguans in general are more religious than most Cubans were during the 1959 Cuban revolution led by Fidel Castro.

The expulsion of the foreign priests is an especially delicate point for the Nicaraguan church because a large percentage of priests here are foreigners.