pain's political leaders converged on the capital tonight for a final flurry of rallies before the midnight close of their campaigns for Thursday's general elections.

Excitement in the city was visible as cars filled with supporters of each of the five principal parties packed Madrid's main boulevards flying the colors of their candidates. But as the hectic, three-week campaign wound down into a pre-electoral "day of reflection" Wednesday, when all politicking is banned, it was clear that the race, in which 27 million Spaniards are eligible to vote, is between two men only -- Socialist Felipe Gonzalez and rightist Manuel Fraga.

What is perhaps the most starkly drawn choice between left and right that Europe has seen in many years is the result of the breakup this year of the centrist coalition that has ruled Spain since the death in 1975 of dictator Francisco Franco. At the same time members of the ruling Union of the Democratic Center party moved to each side of the middle, the Communist Party suffered its own splits, losing members to the Socialists.

At his final campaign rally tonight in Madrid, with entertainment provided by Miguel Rios, Spain's equivalent of Mick Jagger, and Paco Ibanez, the long-exiled poet and folk singer of the songs of the Spanish Republic, Gonzalez returned to the moderate themes he has echoed throughout the race. His campaign manager, Julio Feo, calls them "Kennedyesque" -- ethics in government, solidarity, change, reconstruction of democratic institutions, pride in a Spain that has been "abandoned and mistreated by the right."

"In the past 25 days," Gonzalez told an ecstatic crowd estimated at more than 200,000 at Madrid University, "I have traveled 20,000 kilometers across the country. Everywhere, I have seen faces filled with . . . hope. What is needed in Spain is a strong government. The people want someone who can recapture the ethical impulse, the joy in working." What the Socialists want, he said, is "Don Quixote, for everyone."

"I offer you a pledge and, I ask you for a pledge -- a majority that wants freedom and justice for all," he said.

Although Gonzalez is expected to win a clear plurality, giving Spain its first leftist government since the Civil War began in 1936, the remaining question is whether his Spanish Socialist Workers Party will take an outright majority of the 350 parliamentary seats.

If it does not, having already ruled out a coalition with the Communist Party, Gonzalez will be forced into accepting a minority party from the dregs of the center.

Socialist sources say it is unlikely that Gonzalez would chose the UCD, whose leadership was taken over by Landelino Lavilla when the government of current minority Prime Minister Leopoldo Calvo-Sotelo collapsed last summer.

Following months of defections, the last straw against Calvo-Sotelo was the withdrawal of UCD patriarch Adolfo Suarez, who began the party after Franco's death. Suarez formed the Social Democratic Center, a sort of one-man band of a party that offers the former Spanish leader's personal likeability and prestige and little else.

If such a coalition appears necessary, the Socialists clearly prefer Suarez. For his part, the 50-year-old former prime minister has not only offered himself, but said he believes such a pact is the only road to democratic stability. "The pact between political groups that we are proposing," he told a rally in Barcelona yesterday, "could be the only way to effectively confront the large issues that are before us."

Despite the talk of a left-center coalition, Gonzalez says that only an absolute majority will enable the Socialists to govern effectively.

The largest issue, according to many Spaniards, is whether the country's military and conservative business and political elite can tolerate a strong leftist government.

The loudest voice against it is Fraga, 60, a former Franco minister whose unrepentant right-wing views kept him in the political wilderness when democracy was restored. His Popular Alliance Party has benefited, however, at least as much as the Socialists from the centrist split and is expected to win as many as 85 to 90 parliamentary seats. Billing himself as a "liberal-conservative," he has outlined the choice as one between stability and chaos.

"There is no other way now," he said in a nationwide campaign broadcast last night, "than to choose between two very clear options. One is moderate, reformist, liberal, conservative. The other is the utopian change envisaged by the Socialists."

At a rally here tonight of 50,000 supporters Fraga said, "Socialism will set Spain back centuries."

A Communist Party rally at the bull ring, where the grand old lady of the party, Dolores Ibarruri, appeared on the platform with party leader Santiago Carrillo, drew only about 15,000, the Associated Press reported. The outgoing UDC hadcalled off its rally earlier.