Leopoldo Calvo-Sotelo failed a first test of his nomination to become Spain's prime minister tonight, receiving 169 votes in the 350-member Congress of Deputies, seven short of the absolute majority required for election in the first round of voting.

At the end of a three-day nomination debate, Calvo-Sotelo said he would seek a second-round vote scheduled for next week, when he will need only a plurality to be elected. He was opposed by 158 deputies, mostly from the Communist and Socialist parties and faced little difficulty winning in the second round.

But the decision of members of conservative and regional nationalist minority groups to abstain in the vote indicated that Calvo-Sotelo will be heading a minority government. His predecessor Adolfo Suarez had survived nearly five years in office with the support of such groups.

Fueling what has become a major crisis in Spain's still rocky democratic system, Basque terrorists seized three honorary consuls in a spectacular overnight operation.Groups of armed gunmen seized the representatives of Austria and El Salvador in Bilbao and the Uruguayan consul in Pamplona. A fourth raid on the residence of the Portuguese consul in San Sebastian failed because the consul was absent.

The kidnapings apparently were carried out by the Marxist ETA separatist organization to focus world attention on the death of an ETA suspect in police custody last week.

Relatives for kidnaped Uruguayan Consul Gabriel Biurrun, 49, said the gunmen had told him to pack a suitcase and told his family he would be held for several days. The other victims were identified as Austrian national Herman Diez de la Sel, 45, and Antonio Amparo Fernandez, 47, a Spanish national representing El Salvador.

The torture allegations have cost a shadow over the congressional debate on Calvo-Sotelo's nomination and have been a key factor in the withholding of minor party support. The death of ETA suspect Jose Arregui was exploited by ETA and Basque extremists who staged widespread strikes and demonstrations earlier this week. The public outcry served to halt, at least momentarily, a trend of public feeling against ETA and in favor of Basque moderates.

Calvo-Sotelo insisted during the debate that he intends to form a minority government drawn from the Union of the Democratic Center to which both he and Suarez belong. Opposition parties on the left and right of the ruling centrists predicted that the premier-designate would be forced into midterm elections within a matter of months.

Calvo-Sotelo has presented a government program with the accent on economic issues and giving priority to fighting unemployment, now running about 12 percent.

He said his main foreign policy goal was to join the European Common Market and he favored bringing Spain into the North Atlantic Treaty Organization (NATO).

Adding to the atmosphere of crisis was the political storm caused by the resignations of senior police officers to protest the criticism that followed the death of the ETA suspect. The Interior Ministry confirmed today that a threatened chain of resignations had been halted, and that only seven had been accepted.

The unprecedented protest underlined the difficulties that Calvo-Sotelo will be facing over the coming months with the double threat of renewed terrorist activity and a security force that appears to be nostalgic for the Francoist system that built it up.

The crux of the political crisis, however, was the consensus opinion that Spain's democracy is treading new ground both because of the departure of its main architect, Suarez, and because of the decision of his designated successor, Calvo-Sotelo, to govern alone from a minority position. d