The consensus is dead in Spain, killed by its own father, Premier Adolfo Suarez.

He did this two weeks ago by naming the most conservative Cabinet Spain has seen since the end of Franco era three years ago.

For Suarez, the consensus apparently had outlived its usefulness.

The consensus was the remarkable system of government Suarez used for peaceful transition from the Franco dictatorship to a classical West European parliamentary democracy presided over by a young king hand-picked by the dictator.

Under the consensus, moderate Francoists, their moderate opponents and the Socialists and Communists were invited to join hands in writing a democratic constitution that would overcome the eternal split in the Spanish psyche between victors and vanquised-between Catholicism and nationalism on one side and Marxism and anticlericalism on the other.

Only too glad to get a chance at respectability after 40 years of repression and hostile propaganda directed against them, the leftist parties outbid each other in attempts to cooperate with Suarez's center-right government. What was less well understood was that Suarez then needed the left as much as it needed him to give the Franco moderates a new democratic respectability at home and abroad.

With these democratic credentials provided by the left, Spain could fulfill the dream of joining the Europoean community and the Atlantic Alliance, ending decades of isolation from the rest of Europe.

With the constitiution finally in place after more than two years of painful negotiation among the parties of the consensus - and with the first regular elections under the new national charter having confirmed the Suarez party as a near-majority - Suarez signaled by his choice of a Cabinet that the right means to govern alone and consign the left to the role of his majesty's loyal opposition.

Ths Socialist Party, angered that Suarez did not even bother to seek parliamentary approval for installation of his new Cabinet, was reduced to forcing a debate about reorganization of ministries that Suarez ordered. But there is no chance that the opposition can upset the government.

Suarez demonstrated just how much he feels he is in control by naming his conservative Cabinet just two days after the first municipal elections in 40 years had swept the left to its expected victory in Spain's major cities. Suarez agilely minimized the electoral impact of the municipal polling by maneuvering to hold the local elections only after the national parliamentary elections in which his party triumphed March 1. This enabled Suarez to prevent the bandwagon effect the Socialists had been counting on to bring them to national power.

The premier has now dropped from his Cabinet the man who had served as the bridge between Suarez's Center Democratic Union and the Socialists, Finance Minister Francisco Fernandez Ordonez, head of the Social Democratic Party. Fernandez had not hestitated to tell visitors that he was constantly torn between his desire to join the Socialists and his desire to keep his group under the Suarez umbrella organization.

An even more remarkable sign of Suarez's shift to the right was the appointment of Gen. Antonio Ibanez Freire, a veteran of the Franco forces in the Spanish civil war, to replace a civilian as head of the Ministry of Interior.

Despite his record, Ibanez has proven to be a moderate in the mold of Suarez, who was himself the last minister of the National Movement, the only legal party under Franco.

The choice of Ibanez to head the police and be responsible for law and order while the Basque country in particular is challenging Spain's continued existence as a centralized unitary state is a clear signal to the restive officer crops. Since they did not like how moderate civilians handle the problems, one of their own can now try his hand at doing better.

Suarez also signaled that there will be limits to the power of the regional governments authorized under the constitution. He appointed as head of the Ministry of Territorial Administration, Antionio Fontan, a dedicated monarchist and a member of Opus Dei, the conservative Catholic group that animated the Franco government's conversion of Spain to a modern economy.

Fontan has expressed ideas about regionalism somewhere between the absolute centralism of Franco and U.S. style federalaism. For him, the monarchy is the essential ingredient to keep Spain united.

At the Defense Ministry, Suarez apparently decided to have the best of both worlds by appointing as minister a conservative civilian, former industry minister Augustin Rodriguez Sahagun, but under the authority of the former minister, Gen. Manuel Gutierrez Mellado, who remained as vice premier for security and national defense.

With 168 seats in the 350-member lower house of parliament, Suarez won his investiture by recruiting nine rightist deputies and the five members of the autonomist Andalusian Socialist Party to his side. He repaid them with no Cabinet seats. The only group outside his own party to gain any Cabinet recognition was the armed forces, with its two generals.

Communist leader Santiago Carrillo, in many ways Suarez's most loyal partner in the consensus period, predicted that the premier could not rule for long with such a Cabinet.

Meanwhile, however, the Communists found themselves with no choice but to revive for the first time their precivil war alliance with the Socialists to rule the large cities. In the 100 largest towns, the Socialist, Communists and regional autonomists won 1,500 of the city councilmen out of 2,600.

Suarez apparently thinks the pattern of politics in France and Italy, where the voters express leftist sympathies when the stakes are limited but vote for the right when there are basic national choices, can be made to work in Spain as well. His advisers have been saying that if he keeps playing his cards properly, his party can stay in power for 100 years. He is acting as if he believes it. CAPTION: Picture, PREMIER SUAREZ . . . signals new confidence