It has been billed as the key to the votes of 6 million Spaniards, 20 per cent of the electorate, who are still undecided two weeks before the 6 June elections.
Mr Aznar may be behind on inches but the two latest opinion polls published yesterday showed him to be edging ahead on likely votes. One, for the conservative daily El Mundo, gave his Popular Party (PP) 35.2 per cent of the vote, or between 144 and 153 seats in the 350-seat parliament.
Mr Gonzalez's Socialists registered 34 per cent, or between 134 and 143 seats. That would leave the balance of power in the hands of the mainly Communist United Left (IU) as well as the regional Basque and Catalan parties.
The other, by the Abaco organisation and also published in the conservative press, gave the PP an even stronger lead, of between 30 and 40 seats. But it was based only on decided voters and noted that the 6 million undecided could push the vote either way. It has been a feature of recent opinion polls that they have tended to show an advantage for the party whose policies are closest to the newspapers that published them.
Tonight's debate, on the private Antenna 3 channel, partly owned by Rupert Murdoch, is seen as make-or-break for Mr Aznar, generally billed as uncharismatic. He is facing one of world politics' greatest communicators, Mr Gonzalez. Spain's equivalent of 'The Kinnock Factor' is generally seen here as the biggest obstacle to a PP victory in a country - even Mr Gonzalez admits it - crying out for change.
Mr Gonzalez, however, is looking increasingly tired of politics, while Mr Aznar, 40, is clearly hungry for victory. If you cannot be born charismatic, perhaps you can achieve it or at least have it thrust upon you. PP officials are already working on ways for the television studio's make-up artist to play down Mr Aznar's dark eyes which, along with his small but thick black moustache, have earned him the nickname 'Charlotin' (Charlie Chaplin) from his opponents.
The import being given to the debate here is, apart from that 20 per cent 'undecided' figure, for one very good reason. Relatively few Spaniards read newspapers but they watch more television than in most other European countries. 'La tele' (the box) is the key to the hearts and minds of the nation.
Regardless of the entertainment value, not everyone favours copying the US approach. The IU leader, Julio Anguita, tried to prevent the face-to-face debate through the courts, saying it was illegal since his party is a key player in the elections. He wanted, if you like, to be the Ross Perot. A court rejected his complaint, and it will be one-on- one tonight.
The debate will go out in prime time for Spain, starting around 10.15pm and likely to run close to midnight. A 'second leg' will be held next Monday.
Meanwhile, the two big party leaders continued to attack each other during weekend campaigning around the nation. While the PP's campaign centres on the present - 'Now, PP' say its posters - and the Socialists' slogan is 'Vote for the future', the past still dominates. Mr Gonzalez continued to raise the spectre of the long Franco dictatorship while Mr Aznar, not surprisingly, focused on what he considers the failures of 10 years of Socialist rule.Reuse content