Hundreds of thousands of Spaniards marched through major cities for peace on Saturday, two weeks after the Basque separatist group ETA shattered its nine-month permanent cease-fire with a massive car bomb.
But bickering over slogans and government policy on ETA led the main opposition Popular Party to boycott the march in Madrid, the first time a major party has not attended an anti-ETA protest since democracy returned to Spain in the 1970s.
Similar squabbles also prompted other groups to stay away from the demonstrations, which came after ETA claimed responsibility for the bomb that killed two people at Madrid's Barajas airport.
The conservative Popular Party had said it would only join the Madrid march if its slogan contained the word "liberty".
When this was inserted by the organisers, the party decided not to join anyway and demanded that the marches in the capital and the northern city of Bilbao be called off, accusing the government of having no realistic anti-terrorism policy.
The Madrid march finally got under way under the slogan "For peace, life and liberty and against terrorism". Madrid's regional government estimated attendance at 210,000.
Batasuna, the banned political wing of ETA, refused to join the Bilbao march because the slogan there included the phrase "We demand ETA ends violence". Bilbao officials said 80,000 took to the streets of the Basque city.