On 29 April 2003, the Spanish Police, following judge Garzón’s orders, arrested eight members of Udalbiltza: Miriam Campos, Eider Casanova, Lander Etxebarria, Oskar Goñi, Leire Idoiaga, Txema Jurado, Larraitz Sanzberro and Karmele Urbistondo. 24 hours later, the detainees were taken to make their statements to the judge, who sent all of them to jail. Meanwhile the Spanish police searched and sealed off Udalbiltza offices in Astigarraga, Bilbo, Gasteiz e Iruñea and seized the material in the offices.
Thus, Garzón provisionally suspended Udalbiltza’s activity and accused it of being “an instrument for ETA‿. The detainees were charged with membership of ETA and of promoting the creation of AuB and the local election platforms following its orders.
In order to respond to this attack, Udalbiltza representatives met, in Astigarraga town hall, with representatives from the fields of politics, Basque cultural activities, culture and trade unions and various other social agents. On the other hand, elected representatives from scores of town halls held an emergency meeting in Astigarraga fronton (Basque hand-ball court). Finally, after two and a half years with no meetings whatsoever, the two expressions of Udalbiltza met in order to foster cooperation following the police raid.
In this context, Maribi Ugarteburu, spokesperson for Udalbiltza, spoke to the media and highlighted the series of events: “we do not believe in coincidences, as the police raid has taken place 48 hours after Udalbiltza restated its decision to continue work and at a time when the presence or otherwise of a political option in an election is about to be decided‿

“This was an announced raid. Although he isn’t charging us with any crimes, judge Garzón has filled 35 pages with Udalbiltza’s political activity‿, said the mayoress of Amoroto.
Finally, Ugarteburu issued a call: “Let us not forget that Udalbiltza is made up of many more people than the detainees. It is an assembly of elected representatives and, therefore, I would like to call on all of them to leave their party affiliation aside, learn from our misfortunes and all together support Udalbiltza and help it to continue forward‿.
As a result of the meetings held, a national demonstration was announced for May 10, under the motto: Bai Udalbiltzari, Bai Euskal Herriari (Yes to Udalbiltza, Yes to the Basque Country).

Several hundred municipal representatives held an extraordinary assembly on May 7, at the Leidor Theatre in Tolosa in order to “issue a call for dignity, in view of the serious political situation‿.