Country profile: Spain Just two months ago Spain's general elections produced a surprise defeat for the conservative Popular Party (PP), which had governed for eight years, and saw the return to power of the Socialist Party (PSOE).
The elections were held on March 14th, only three days after the terrorist attack that killed 192 people and injured more than 1,500. Spaniards had been overwhelmingly opposed to sending their troops into Iraq, and it is widely believed that the Spanish capital was the target as a reprisal for Spain's role with the US-British coalition.
PP officials say that the emotions roused by the massacre caused some PP voters to switch to PSOE, and prompted others, who would have otherwise stayed away, to cast their votes.
The new Prime Minister, Mr José Luis Rodríguez Zapatero, denies that the European elections are a re-run of the generals, but he has called for a high turnout to prove that the general elections were a true barometer of public opinion and not an emotional backlash.
Recent polls show the socialists have increased their majority since March 14th, and are now some 4 percentage points ahead of PP.
Six political groups and alliances have presented their lists for the elections. The socialists, who have joined with the Greens on this occasion, are led by a Catalan, Mr Josep Borrell, an economics professor and public works minister in the Felipe Gonzalez government. He is followed by two experienced European parliamentarians, Ms Rosa Diez and Mr Enrique Barón.
The number one slot on the PP list is Mr Jaime Mayor Oreja, the Basque politician and the interior minister in José Maria Aznar's first government.
Three major regional parties, the Basque PNV, Catalan CIU and the Galician BNG, have joined forces to form the Galeosca grouping. One of the most controversial lists was that presented by the Basque Herritarren Zerenda (HZ), which has been accused of being little more than a new name for the banned Herri Batasuna (HB), the political front for ETA.
The attorney general appealed to the supreme court to prevent them receiving copies of the electoral lists which would have given them information on voters. He said 33 of the 56 candidates on the HZ lists had "clear links to HB and/or ETA".
There will almost certainly be one element in these elections that sets them apart from previous Spanish elections. In spite of repeated demands from the opposition, the former prime minister Mr Aznar has refused to meet his opponent in front of the cameras. But Mr Borrell and Mr Mayor have agreed to hold a face-to-face debate on prime-time television on a date yet to be set. In addition there is likely to be a six-band debate with the leaders of all the groups pressing their points, after the United Left and the regionalists complained of "discrimination".
Mr Borrell and the socialists have adopted "Volvemos a Europa" (we are returning to Europe) as their campaign slogan to stress their "Europeanism" after what they described as PP's Euroscepticism. Mr José Blanco, the PSOE organisational secretary and campaign co-ordinator, said this week: "Spain has returned to the heart and the motor of Europe."
Mr Mayor Oreja said his PP party had an open mind on the European constitution. "We want to support it because we have been protagonists in it for so long. Now there are others who have to negotiate and they will say exactly what they want. But Spain must keep the same weight that the (PP) government negotiated in Nice."
Even before the campaign has really started, some candidates have brought up Spanish involvement in Iraq, in particular the recent revelations of torture. Mr Mayor Oreja retaliated: "The war must not be a topic in the campaign." But he warned that if the socialists insisted, he too would go back further and bring up the torture and GAL dirty war against ETA which occurred under the 1982-1996 socialist government.
Another controversial issue is where the constitution should be signed. After the March 11th bombing, European leaders agreed that Madrid should host the ceremonies. But during a recent visit to Italy, Mr Zapatero said that they would be held in Rome, where the first treaty was signed some 50 years ago. Mr Mayor Oreja has demanded to know the reasons for this change of heart. "The victims deserve Madrid for the ceremony," he said.