Mr Aznar (left) and his successor disagree over troops in Iraq

Socialist leader Jose Luis Rodriguez Zapatero said Spaniards had reacted bravely and would fight terrorism.

The Madrid bombings which left 190 dead have been blamed on Islamic extremists.

Senior US officials said voters had appeased terrorists by rejecting Jose Maria Aznar's government - a key US ally in the war on Iraq.

Many Spanish voters said it was Spain's involvement in the war, which went against overwhelming popular opposition, that had provoked the 11 March attacks.

Mr Aznar's conservative Partido Popular (PP) had been widely expected to win a third term in government. But the train bombings are considered to have provoked a higher turnout in the elections three days later - in favour of the opposition Socialists (PSOE).

Terrorism must know that it will face us all and that united, we will defeat it Jose Luis Rodriguez Zapatero, Prime minister elect

Mr Zapatero, addressing his party on Friday, dismissed the accusations of appeasement made in the US by Republican congressman Dennis Hastert, among others.

He said Spain had lived with attacks by militant Basque separatists Eta for more than 30 years, well before the 11 September 2001 attacks on the US.

"We did not discover the ruthless face of terror three years ago," he said.

He said claims that his election victory was due to Spanish voters being scared of terrorists were "simply indecent".

Iraq troops

Mr Zapatero praised Spain's reaction to the attacks, particularly the passengers on the trains who stopped to help others rather than fleeing; the work of the emergency services and the way millions took to the streets to demonstrate against terrorism only a day after the atrocity.

He said Spain would continue to fight terror.

"My most immediate priority is combating all forms of terrorism," he said. "Terrorism must know that it will face us all and that united, we will defeat it."

Mr Zapatero said he would pull troops out of Iraq without UN action

Mr Zapatero's speech did not refer to Iraq or his election pledge to withdraw Spanish troops unless the United Nations played a greater role.

But he said his government's foreign policy would bring Spain back to the "front lines in the defence of international law and of a world order based on multilateralism and in the defence of the authority of the United Nations".

Mr Aznar, speaking at the EU summit in Brussels, again defended the decision to send troops to Iraq.

He said: "My view is that to remove Spanish troops from Iraq is a calamitous error for Spanish policy."

Mr Zapatero is expected to take office in April.