Guatemala's civilian vice president had resigned from the country's military-dominated government and taken refuge in Washington, charging the generals in Guatemala City with failure to make good on promises to permit free labor unions and political organizations.

Francisco Villagran Kramer, an internationally-known lawyer and liberal politican, accepted the vice presidency two years ago as part of a compact between civilian political leaders and the military president, Gen. Romeo Lucas Garcia, designed to broaden the political base of the government.

Villagran submitted his resignation by letter Monday and in an interview yesterday said he had "come to the conclusion that the [Lucas] government participated in a cover-up of the assassinations" of several prominent center-left politicians.

Villagran, 53, said authorities had persistently refused to order ballistics tests or checks of autos used in the killings of economist Alberto Fuentes Mohr and other leaders over the last two years.

Guatemala stands accused by most human rights organizations of major violations that rarely result in prosecutions and frequently are believed to have been abetted by the government.

Villagran denounced "the persistent harassment of the Indians," who are a majority although largely on the margin of society in that Central American country. He corroborated reports that as a result, the Indians increasingly are offering at least tacit support to leftist antigovernment guerrillas.

Extreme rightists, in an out of the government, hounded him into exile, Villagran said While he said the exile was voluntary, Latin American and U.S. diplomats were unanimous in stating that Villagran's life had been in jeopardy at home.

While denouncing the extreme conservatives that dominate the government, Villagran was also harsh in criticizing the extreme left that seeks power through guerrilla war.

"May effort was to avoid a Custer's last stand in Guatemala," he said. "But the extreme left wants it, the right is so disposed and the government now is also."

Villagran said that despite the virtual elimination of moderate leaders, some hope remains for national understanding. "But now the dialogue must be between the newly politicized unions and the ownership class," which he accused of refusing to accept justified demands of labor. And, he added, "the miliatry has to learn to sit down at the table too, and to listen to criticisms."

Recounting a last, frustrated effort on the part of social democratic and non-Marxist socialist parties to make these points with the military, Villagran said the U.S. State Department, while encouraging, had avoided involvement.

Although generally aproving of U.S. policy in regard to Guatemala as well as nearby Nicaragua and El Salvador, Villagran said:

"The Carter administration has great experience with governments of the right in America but little experience with governments of the Left. Since it doesn't have that experience, it often gives the impression of having doubts."

Villagran said he is polishing up a proposal that the United States, in permitting contracts for purchase of such goods as Guatemala's cotton and sugar, insist that workers involved in producing such goods receive wages on a par with the rest of the world.

The crux of the exploitation of Guatemala's Indian population he said is that the export industry takes advantage of needy and unorganized workers by paying poor wages.

Asked about what is often described as the inevitability of violent revolution in Guatemala, Villagran recounted a recent meeting with 15 students at Guatemala City's San Carlos University, whose faculty is a persistent target of right-wing assassins.

"All 15 students violently condemned the government," he said. But only five said they were for a violent guerrilla alternative. So there are still some doubts."

Following Viligran's resignation Monday, the Congress elected a retired colonel, Oscar Mendoza Azurdia, to replace him. The same congressmen had accused Villagran, he recalled, of being an agent of both the United States and the Soviet Union.