Madrid — The crisis over the Falkland Islands, once a colonial possession of Spain, is causing considerable political fallout here.
Passions have become so strong that even in parliament some moderate deputies have begun to question the value of Spain joining the Atlantic alliance, and have urged instead a more neutral stance and the strengthening of Latin American ties.
Throughout the crisis, Spain has supported the Argentine claim over the islands and has condemned British use of force as ''an historical error.'' Spain was the only European country to abstain on the UN Security Council resolution 502 that asks for an end to hostilities and the withdrawal of Argentine troops.
Likewise, Spain also abstained from voting in the Council of Europe resolution that supported Britain's claim to the Falkland Islands. Officially, Spain supports a negotiated settlement giving Argentina sovereignty.
But the dispute presents a dilemma for the government torn between emotional and cultural ties with Argentina and a desire to stand firm with its European partners. Europe has backed Britain by applying sanctions against the Buenos Aires government.
Spain's interest in the contested islands has been underscored by King Juan Carlos's recent offer to mediate between Argentina and Britain.
Calling for a ceasefire and the start of negotiations the king said ''I plead to both the European Community, to whom we belong for a variety of reasons and to the Ibero-American community to whom we are linked not only by blood but history itself.''
The offer appeared to be an attempt to forestall criticism within Europe of Spain's anti-British stand so far. Government controlled television has openly sided with Argentina in the conflict referring to Britain variously as ''belligerent,'' ''intransigent,'' ''aggressive,'' and ''colonialist.''
On the domestic political front, the Falklands dispute has produced some surprises in the expected positions of the Socialist and ruling parties as Spain's generally pro-Argentine position was debated in Parliament last week.
Paradoxically, the Spanish Socialist Workers' Party, which has opposed Spain's entry into NATO, supported the continental or ''European'' position. On the other hand, the ruling Union of the Democratic Center Party (UCD), which has given all-out priority to Spain's entry into NATO, has defended Spain's official anti-colonialist stand and third world solidarity.
The Socialists seemed to be conditioned in their stand by the Socialist International and found themselves in the rather curious position of being ''Europeanist'' in spite of their opposition to NATO membership. Socialist spokesman Manuel Marin criticized Spain's abstention on Resolution 502 and claimed Spain had made ''the slip-up of the future.''
Spanish Socialists had been warning throughout the conflict that the official government stand was on slippery ground if parallels were made with Gibraltar.
The Moroccans, they argued, could use the same Argentine logic regarding the Spanish colonial cities of Ceuta and Melilla in Moroccan territory. Socialist representative Luis Solana stated that he was certain the Moroccan embassy had a special task force copying down every Spanish official statement in favor of de-colonizing the Falklands.
Mr. Solana also pointed out that the Secretary-General of NATO, Joseph Luns, recently stated that NATO would not cover Ceuta and Melilla. Solana interpreted this as a warning against Spain's refusal to align itself with the alliance in support of Britain.
Basque and Catalan minority parties, on the other hand, came out in the Falklands debate as clearly Anglophile, accusing the government of not condemning Argentine and British use of force in equal terms. The representative of the Conservative Basque Nationalist party, PNV, recommended that the government ''not ignore where we are geographically and where 80 percent of our commerce takes place.''