At least two of the political parties that have registered to contest elections here next March, both of them on the far right of the political spectrum, have called for the immediate disbanding of the government before campaigning begins.

The newly formed Republican Nationalist Alliance, headed by former military intelligence officer Roberto d'Aubuisson, and Democratic Action, a party led by San Salvador attorney Rene Fortin, have long opposed economic and social reforms advocated by the ruling junta, a coalition of the armed forces and the Christian Democratic Party. These reforms, begun after a coup by young officers in October 1979, have been backed by both the Carter and Reagan administrations.

Last week, the government's Central Elections Council held the first session in a series of "political forums" for the six parties that have registered so far for the March election of 60 deputies to an assembly to rewrite the constitution. With the exception of the Christian Democrats, all are considered on the far right, in varying degrees opposing social and economic reforms and supporting an increased role for the military in government.

D'Aubuisson, who has been accused twice in the past two years by both the U.S. and Salvadoran governments of promoting the overthrow of the junta, called for the immediate removal of the current government. Democratic Action, in what one Christian Democratic leader described as an attempt at a "paper coup," demanded new appointees in the ministries of education, labor, interior and agrarian reform, and the resignation of all mayors and provincial governors, many of whom are Christian Democrats.

The Reagan administration, which strongly supports the government headed by Christian Democratic President Jose Napoleon Duarte, believes that elections will help to legitimize civilian rule in El Salvador and take some of the initiative away from guerrillas now trying to overthrow the military-civilian coalition government in a civil war.

Backed by the U.S. administration, the Duarte government has refused to participate in negotiations with the guerrillas to end the conflict, declaring that the rebels are interested only in using the negotiating table as a stalling tactic to consolidate their military power.

Outside of the six that have registered for the election, the rest of El Salvador's political parties operate outside the country in a political-military coalition with the guerrillas. Although Duarte has invited them to register, provided that they sever their ties with the rebels and renounce violence, they have refused to participate in the election on grounds that past military-run contests have been fraudulent and that the current climate of violence is not conducive to a fair campaign.

As the election date approaches, some Christian Democrats have indicated privately that strong U.S. support for a military solution in El Salvador may undercut both their current leverage with the armed forces and their electoral chances, ultimately frustrating U.S. aims by leaving the government in the hands of the right and the military.

D'Aubuisson's presence in the country marked the first time he has been allowed to return since President Duarte said last spring that he had issued a warrant for the former intelligence officer's arrest. D'Aubuisson had spent much of his time before Duarte's announcement making the rounds of military barracks, distributing leaflets urging the overthrow of the government.

Salvadoran Defense Minister Jose Guillermo Garcia told editors and reporters of The Washington Post in Washington that d'Aubuisson, who had been living in Guatemala, was permitted to reenter El Salvador under a preelection amnesty. Garcia said no warrant for d'Aubuisson's arrest was outstanding.

Almost a year before Duarte said he had ordered d'Aubuisson's arrest, troops loyal to then junta member Col. Adolfo Majano raided a country home on the outskirts of San Salvador and arrested d'Aubuisson and other leaders of the National Action Front, his paramilitary organization. Col. Majano, who ordered the raid, later was arrested himself and sent into exile apparently after losing a power struggle with officers who thought he wanted to move too quickly on implementing social and economic reforms.

Former U.S. ambassador Robert White later said that among the captured documents were maps, coup plans and documents pertaining to the murder of Archbishop Carlos Arnulfo Romero, who was killed by a sniper in March of 1980. A few weeks after his arrest, d'Aubuisson was released and charges against him were dropped.

Christian Democratic Party officials and representatives of the Central Elections Council did not express serious concern about the participation in the campaign of d'Aubuisson and others who have called for the overthrow of the government.

Reminded that d'Aubuisson had been caught twice plotting a coup, Christian Democratic Party leader and Education Minister Carlos Aquilino Duarte said simply, "and so are many others in the current campaign."

D'Aubuisson has defined the ideals of his new party, the Republican Nationalist Alliance as national security, power to the state and the armed forces, "individualism," free enterprise and the struggle against communism.

If all goes according to the current government plan, 1.5 million to 2 million Salvadorans will elect representatives to the constituent assembly from among the six parties now registered. The new deputies will then spend a year drafting a new constitution in time for presidential elections in 1983.

Jorge Bustamante, president of the Central Elections Council, when asked what significance an election with such a limited range of political options might have and what guarantees against frauds there are, answered: "If less than 51 percent of the population votes in March these elections will mean nothing. If the guerrillas do not accept the results and are able to demonstrate that the elections were fraudulent there will be a worse civil war than the current one."