Mr Gonzalez, the Seville lawyer with the choirboy looks, led the Socialist Workers' Party (PSOE) to an overwhelming victory in 1982. He won again in 1986 and 1989, with a gradually diminishing majority and is now going for a fourth term.
But for the first time since his triumph of 28 October 1982, when he tossed red roses at supporters from a Madrid hotel window, he is by no means assured of victory. Polls suggest the most likely outcome is that Mr Aznar's opposition conservative Popular Party (PP) will win a few more seats than the PSOE, though short of an absolute majority of 176 in the 350-seat Congress.
That would leave the communist-dominated United Left (IU), which could win up to 27 seats, and the regional Basque and Catalan nationalists, which together could capture perhaps 27 seats, holding the balance of power.
Mr Gonzalez would therefore need at least the support of the IU and probably further seats in order to govern, and that only if he upsets the polls and wins more seats than the PP. The Basques and Catalans have said they are prepared to deal with either major party, at a price, of course. But they make no secret of leaning towards the man they believe would be more like putty in their hands, Mr Aznar.
The last word might be with King Juan Carlos, who has to ask someone to form a government. In the likely event of a hung parliament, the process of designating a new prime minister could drag on for weeks.
In a coalition with the IU Mr Gonzalez, a centrist social democrat but a closet conservative on many issues, would be dragged kicking and screaming towards the left he has sought to disown.
The IU's communist leader Julio Anguita, still in a Barcelona hospital after suffering a heart attack while campaigning, is fiercely opposed to European unity, which is Mr Gonzalez's obsession.
It was, oddly enough, an election campaign in which the issues were hardly contested. Corruption among the Socialists had been the opposition catchword before Mr Gonzalez decided in April to call a snap poll. Although it appeared to prove what most Spaniards believe, namely that corruption is an all-party phenomenon, the issue discreetly disappeared, apparently after an inter-party deal between the big two.
A Supreme Court judge who had been due to report last Thursday on the biggest alleged PSOE corruption scandal postponed the report until after the elections. This was, he said, so as 'not to interfere with the democratic process'.
It was an economic crisis that led Mr Gonzalez to gamble on an early poll. The economy - with 3.3 million Spaniards or 21.7 per cent of the workforce now jobless, growth zero and falling, businesses collapsing and a peseta devalued three times in nine months - should have been the crucial campaign issue. But Mr Gonzalez simply apologised and promised a complete re-vamp of his policies, while Mr Aznar spouted criticism but offered little in the way of solutions.
And so it came down to the level of personal attacks, and, to a large extent, the shadow of the Civil War and the Franco years. The basic question was: is Spain, 18 years after Franco's death, ready for a return to the right? In his closing rallies in Madrid and his home town of Seville on Friday, Mr Gonzalez continued to play the fear-of-the-right card.
'We knew how to forgive. But we cannot forget. For we know the history of this country,' he told his supporters.
Mr Aznar, in his final rallies in Madrid, where he was born, and Valladolid, where he built his political career as regional Prime Minister, countered that his was a new Right, a young Right, and attacked Mr Gonzalez for seeking 'the fear vote'. After greeting party members with youthful 'high fives', Mr Aznar blasted Spanish state TV and radio for concentrating on Mr Gonzalez's campaign at the PP's expense.
There was little sign of 'Franco's shadow' in Madrid's Palace of Sports as a disco beat pounded and thousands of young people split the darkness, rock concert- style, with cigarette lighters or matches before Mr Aznar ended his campaign with the words: 'Spaniards, we are going to win for Spain.'Reuse content