MADRID Spain's high-profile trial of Islamist suspects of 2004 train bombings in Madrid has turned into a political battlefield thanks to many Spaniards' suspicions that Basque separatists were involved in the attacks.
Investigators and the government accuse a group linked to al Qaeda for the bombings of four Madrid trains on the morning of March 11, 2004, which killed 191 people.
But almost one in five Spaniards believe Basque separatist rebels ETA took part in the attacks, a recent poll showed, even though there is no direct evidence.
Media outlets favoring Spain's conservative opposition Popular Party have championed the ETA theory, turning the public trial of 29 suspected Islamists, petty criminals and a former male stripper into a test for the Socialist government.
In the most heated political exchange to date originating from the trial, Interior Minister Alfredo Perez Rubalcaba accused the head of the police at the time of the attack of lying to the court about an informer telling of ETA links.
The former police boss is now a member of the European Parliament for the Popular Party, which was in power when the bombers struck but bungled its response to the attack and lost elections three days later.
The Popular Party government, which had led Spain into the deeply unpopular Iraq war, initially blamed ETA for the bombings, an accusation which has apparently lodged in the minds of millions of supporters.
"The debate about the conspiracy theory has made relations between the two big political parties much more tense," said Juan Aviles, a contemporary history professor at Madrid's Open University UNED.
"There is a widespread belief that the government does not want the truth to get out," he said.
Arguments in favor of the accused in the trial have also utilized the ETA theory, and one defense lawyer even suggested the Basque separatists were involved in the attack against New York's World Trade Centre in 1993.
With the governing Socialists just slightly ahead of the Popular Party in opinion polls, the result of national elections in a year's time is a difficult call, making the trial and its outcome more significant.
"A great deal of the divisions in Spanish society and politics now come from the March 11 attacks," said Gabriel Moris, who lost a son to the bombings.
Moris, a retired industrial chemist, is now vice president of the Association of Victims of Terrorism, which organized several huge anti-government demonstrations in Madrid earlier this year.
Marchers held banners calling for the "truth" about the attacks to be revealed and linking Prime Minister Jose Luis Rodriguez Zapatero to ETA.
They also chanted slogans against the government's attempts, which seem to have failed, to negotiate a peace deal to end ETA's armed struggle for Basque independence.
"The government has placed itself in the hands of terrorists," said Moris, referring to the negotiations, which infuriated Spanish conservatives.
The opposition accuses the government of continuing to deal with ETA, even though Zapatero publicly ended the peace process after a bomb at Madrid airport last December.
So far, the trial has not thrown up evidence ETA had anything to do with the 2004 train bombings, and the Popular Party leadership has begun to distance itself from the theory of their involvement.
"I think the conspiracy theory is going to take a battering," said Aviles.