Hundreds of thousands of Spaniards, from Bilbao in the north to Seville in the south, took to the streets last night to demonstrate against the killing of the leading Basque Socialist Fernando Buesa and his bodyguard.
Mr Buesa's coffin was carried through the streets of Vitoria to the Cathedral of the White Virgin for a funeral Mass conducted by the Bishop of Vitoria, Mgr Miguel Asurmendi.
Tens of thousands of people followed the cortege as it wound through the streets from the parliament buildings to the cathedral. Many thousands more packed into Madrid's Puerta del Sol in protest at the bomb attack, which police say was the work of the Basque terrorist organisation ETA. Some protesters carried banners saying "ETA no, We want peace", while others chanted "Murderers, Fascists!".
The demonstration was attended by the Spanish Prime Minister, Mr Jose Maria Aznar, the Socialist leader, Mr Joaquin Almunia, and national and regional politicians.
The day was one of high emotion and anger throughout Spain. In Zaragoza, Yoko Ono, widow of John Lennon, joined a protest on the steps of the town hall, only three days after denying her husband had contributed money to the IRA.
The day began in Vitoria with a ceremony in the Basque parliament where the speaker, Mr Juan Maria Atutxa, condemned the killings.
Mr Buesa's seat in the chamber was soon covered in flowers from his fellow deputies. His coffin and that of the Basque police officer, Mr Jorge Diez, stood throughout the day in the parliament building as hundreds of mourners filed past.
Although ETA called off its truce at the end of December and it killed an army lieutenant-colonel in a similar car-bomb attack in Madrid a month ago, it now appears that it was active throughout the 14-month ceasefire. The three cars used in the Madrid and Vitoria bombings were all stolen at a time when ETA had officially laid down its arms, and the explosives used came from 10 tonnes of dynamite stolen in France last spring.
The latest attack, just three weeks before Spaniards go to the polls on March 12th, has caused a serious rift in Basque politics. For the past year the moderate Basque Nationalist Party (PNV) has governed in a pact with ETA's political front, Euskal Herritarrok (EH).
The Basque President, Mr Juan Jose Ibarretxe, said the pact was now "definitively broken", leaving his party in a minority of 27 seats in the 75-seat chamber.