Earlier a senior member of Herri Batasuna, Patxi Zabaleta, said there were no political reasons to justify ETA's decision which went against the will of the Basque people.

BBC: ETA political wing calls for calm

The Basque branch of the People's Party, the conservatives who hold power in Madrid, showed an even sharper rise: to 16 seats, up from 11.

ECONOMIST: Spain��s Basques

Mr Aznar particularly wants people who live in the Basque country but are not Basque nationalists to vote next month.

ECONOMIST: Spain and the Basques

Mr Aznar may now try to set up a rival front of parties in the Basque country, made up of his own conservative People's Party and the Socialists, who both want to keep Spain's existing constitution, with its strong measure of regional self-government but with no option for independence.

ECONOMIST: Spain and the Basques

In 1996, Mr Aznar had to offer the Basque and Catalan nationalists more devolution to get them to support his conservative People's Party in the Madrid parliament.

ECONOMIST: Spain

After all, the authors point out, most people in Spain's minority regions see themselves as both Spanish and Basque (or Catalan or Galician) not just one or the other.

ECONOMIST: Diversity and development | The

In March 2004, luck helped to bring the leader of Spain's Socialists to power: he was trailing in the polls until a cack-handed attempt by the ruling centre-right People's Party to blame the Madrid train bombings three days before the election on Basque separatists.

ECONOMIST: Spain's election

It sees the dispute as a purely bilateral matter between the two governments and conceding any form of self-determination for the people of Gibraltar would set an unwelcome precedent that might be exploited by the separatist movement in the Basque country of northern Spain.

BBC: Reshuffle sparks Gibraltar talks fears

Spain's Interior Minister Mariano Rajoy on Thursday called the list a "great step forward" because it included several organisations linked to ETA, which has claimed the killings of 800 people in a 33-year shooting and bombing campaign to secure independence for Spain's northern Basque region.

CNN: EU names terror groups