Spain has ruled out an inquiry into whether Iraq had weapons of mass destruction before the US-led invasion.
Spain has more than 1,300 troops in Iraq
Spanish Foreign Minister Ana Palacio said she would not follow the British and US decisions to hold inquiries into the intelligence used before the war.
Ms Palacio said Spain had supported the war on the basis of reports from the United Nations.
Last week a former US chief weapons inspector said that Iraq did not have stockpiles of banned weapons.
Jose Luis Zapatero, leader of the Spanish opposition PSOE, has called on the governing Popular Party to account for what he called "the lies" surrounding the government's reasons for going to war.
PSOE spokesman Jesus Caldera said the party had also demanded the declassification of secret documents from the Spanish intelligence services.
But Ms Palacio told Europa Press agency: "The position of the Spanish government was always adopted, and at all times, on the basis of data and a consensus which existed at
the United Nations.
"As everyone knows, there was a consensus on the need to disarm, which was written into several UN resolutions."
She said the consensus was "total" and included international leaders who were opposed to war and sought to disarm him by other means.
"I don't have to show that they (weapons of mass destruction) exist," she said. "They existed and Saddam Hussein's regime is asked to say where they are."
Government spokesman Eduardo Zaplana also ruled out an investigation.
He said the Spanish Government had been "and is absolutely coherent" on the issue, adding that the government line was "the best for the national interest and that of world security".
A majority of Spaniards were said to have opposed their government's support for the conflict despite a failure to get a UN resolution backing military action.
Ten Spaniards have died since 1,300 soldiers were sent to Iraq in August.
Spanish PM Jose Maria Aznar backed Bush's war plans
When Spanish Prime Minister Jose Maria Aznar backed the conflict in February last year he told Antena 3 television: "You may be sure, as may all the people watching this, that I am telling the truth.
"The Iraqi regime has weapons of mass destruction, it has links to terrorist groups and has shown throughout its history that it poses a threat to everybody."
He later told TVE state television: "I am absolutely convinced that these weapons, which exist, will appear."
US President George Bush's creation of a bipartisan committee to look at its Iraq intelligence on Monday appeared to raise the pressure on the UK to launch its own investigation.
The UK followed suit on Tuesday, announcing an independent inquiry to examine intelligence which led to the decision to go to war.