One is a Cuban priest who wrote letters criticizing Fidel and Raúl Castro. Another is a Catholic layman who collected 25,000 signatures seeking change. The third edited a church journal muzzled under government pressures.

The Rev. José Conrado Rodríguez, Oswaldo Payá and Dagoberto Valdés are the best-known Catholics who regularly and aggressively attack Cuba’s communist system — and sometimes even their own church leaders.

All plan to attend the Masses that Pope Benedict XVI will celebrate in the eastern city of Santiago de Cuba and in Havana during his March 26-28 visit. But they are not likely to be seated in the front rows.

Rodríguez, 59, has long been a thorn in the side of a government that was officially atheist from 1962 to 1992, and to this day bans Catholic schools and requires prior permits for street processions.

Sometimes called the “people’s cardinal,” he first made headlines in 1994 with a letter blaming Fidel Castro for the island’s financial and social crisis, and urging him to open a dialogue with dissidents and exiles.

The church sent Rodríguez to study in Spain in 1996 — supporters say church officials wanted to protect him, at the same time get him out of the way — and he returned just before Pope John Paul II visited Cuba in 1998.

In 2007, State Security agents burst into his Santiago parish, Santa Teresita del Niño Jesús, to beat and arrest at least 15 young dissidents. The barrel-chested, blunt-talking Rodríguez branded the raid a “terrorist party.”

He followed up with a letter to Raúl Castro in 2009 complaining that “the daily difficulties are becoming so crushing that they sink us deeply into sadness, hopelessness . . . [and] a widespread sense of being defenseless.”

“We are at such a critical moment that we must undertake a profound revision of our criteria and our practices, of our aspirations and our objectives,” the priest wrote. Castro did not answer.

Rodríguez later reported that State Security agents had told his superiors that he was “the only thing standing in the way of good” church-state relations, according to a U.S. diplomatic cable made public by WikiLeaks.

He also told U.S. diplomats in Havana to watch what Raúl Castro does, not what he says, and that he would not be surprised if there’s a “social explosion” on the island, other WikiLeaks cables noted.

Rodríguez also has been critical of Cuban Cardinal Jaime Ortega, and another WikiLeaks cable quoted him as saying that although the church has a role to play in the island’s future, “it is not stepping up to the plate.”

Although other priests in Cuba quietly complain about the communist system, Rodríguez argues that the island’s church has failed to carry out its “prophetic mission” — the requirement that it publicly denounce wrongs.

Church officials transferred him last summer from Santiago, Cuba’s second largest city, to the nearby rural village of El Cristo. But he remains in Santiago, apparently because his replacement has not yet arrived.

Soft Oppositionist

Cuba’s best-known Catholic dissident is Payá, 59, who founded the Christian Liberation Movement and launched the signature-gathering Varela Project — neither recognized by the government.