Thousands of Spaniards -550.000 according to Madrid's conservative government estimates- marched in Madrid on Saturday (November 24) in an anti-government demonstration that highlighted Basque separatist group ETA would be a key political issue in next March's general election. The huge crowds of what must be the world's best-dressed demonstrators, who tend to come from the higher income brackets, thronged the streets waving red and yellow Spanish flags and bearing slogans reading "We'll beat ETA". They also chanted for the resignation of Prime Minister Jose Luis Rodriguez Zapatero. More than 800 people have been killed by ETA in nearly four decades of armed struggle for Basque independence from Spain. The rally is the first organised by a group of ETA victims, the Association of the Victims of Terrorism, since a Spanish court last month found 21 people -- mostly Moroccans -- guilty of involvement in the Madrid bombings of March 11, 2004. High-ranking conservative party officials led the march. Popular Party Secretary General Angel Acebes justified his presence saying that he felt it was a "moral obligation" to show support and defend the "dignity of our country and its recent history." "We entirely subscribe to the march's slogan, 'for a future of freedom, together we'll beat ETA'. What we find absolutely surprising is that the Socialist Party does not subscribe to such a cause," he told reporters. Marchers chanted slogans demanding that the AVN Basque nationalist and the PCTV Basque communist parties be declared illegal and banned from taking part in next year's elections on the grounds that they represent the ETA. Maria San Gil, Basque Country Popular Country president said her group could not agree more with that. "We think is really important to be here today with them, claiming something we understand is the essence of democracy which is the ban of AVN and PCTV, a disguise for Batasuna as everybody knows," said San Gil. Whole families turn out: grandmothers in fur coats; fathers in all-weather jackets and little girls with ribbons in their hair. Alfredo, who came with his son, told Reuters that he found important to be there and show support for the terror victims. "We don't want the president to give into the terrorists' blackmail, not to negotiate with ETA -never, never. We want to beat ETA with the existing tools of a democratic state," he said. Many of the group's members believe ETA was involved in the bombings, which killed 191 people, but the court ruled out the participation of ETA in the attacks. The conservative government in power in March 2004 at first pinned the blame for the attack on ETA, but it became increasingly clear it was the work of Islamist extremists. Spain turned against its leaders and voted them out of power three days later. The demonstration was notable for the absence of conservative opposition leader Mariano Rajoy, whose Popular Party is narrowly trailing the governing Socialists in polls. The government has tried but failed to find a solution to violence in the Basque Country through peace talks with ETA. It broke off the talks in December when the rebels bombed Madrid airport, killing two people. It has since cracked down on the group, arresting dozens for suspected involvement with the outlawed separatists.