Rajoy's ruling Popular Party, under outgoing Prime Minister Jose Maria Aznar, solidy backed the conflict on the grounds that the deposed Iraqi regime was stockpiling weapons of mass destruction -- the rationale used by Washington and London for prosecuting the war.

"The PP government determinedly placed itself alongside those who, on the basis of lies, invaded Iraq. Aznar and Rajoy broadcast and supported these lies," said Zapatero, noting the US government is set to hold a probe into its intelligence on Iraq ahead of the conflict.

Zapatero said governments who had supported the war "have to answer for what they have said and done."

He added that growing doubts over the quality of intelligence reports ought to "open the door" to an enquiry in Spain.

Aznar's government backed the war in the face of huge opposition both from other parties and the public at large.

"They did that overriding the opinion of the vast majority of Spaniards, ignoring the moral indignation provoked among this country's citizens over their unjustified warlike action," the PSOE leader added.

"The PP candidate (for the March 14 general election), who backed the war, must give a public explanation for his actions, his lies and his decisions which led Spain to back this immoral, unjust and illegal war," said Zapatero, insisting the conflict would spark "more terrorism, uncertainty and chaos."

"The (putative) existence of weapons of mass destruction was a false and unacceptable pretext for (US President George W.) Bush and his allies to engage in a war (fought) on the margins of international law," Zapatero insisted.

Spanish deputy prime minister, Javier Arenas, responded to the onslaught by saying that "all the information the Spanish government had on weapons of mass destruction came from UN reports."

"These reports were the basis for government decisions on Iraq," Arenas insisted.

WAR.WIRE