MADRID , Spain ( CNN ) -- Spain 's Supreme Court on Tuesday outlawed a leftist political party for its links to the Basque separatist group ETA , and ordered its immediate dissolution . Supporters of the BMA attend a demonstration in April 2008 . Just hours after the ruling , a bomb was found attached to the underside of a Spanish national police officer 's private car in Bilbao , the largest Basque city , a police spokesman told CNN . The bomb did not explode . The officer had driven it several kilometers to work at police headquarters in Bilbao , where the device was discovered Tuesday afternoon , the spokesman said . Bomb squad experts were trying to deactivate it . The court outlawed the Basque Nationalist Action party , or ANV , as it is known locally . It has about 100 elected town councilors in Basque city halls , and they are expected to lose their seats under the ruling , an analyst told CNN . A lower court judge suspended the party 's activities last February , preventing it from running candidates in Spain 's national elections last March , due to suspicions about its ties to ETA . ETA is blamed for more than 800 deaths in its long fight for Basque independence and is listed as a terrorist group by the European Union and the United States . ETA has sometimes used limpet bombs attached to the underside of the cars of its victims . There was no immediate claim of responsibility for Tuesday 's bomb under the police officer 's car . Spanish courts previously outlawed another political party , Batasuna , for its ties to ETA , and prosecutors and lawyers for the government argued before the Supreme Court that Basque Nationalist Action was a kind of successor to Batasuna . But a Basque Nationalist Action spokeswoman vowed that her group `` will continue its political work '' on behalf of the Basque left , according her comments played on SER radio . Spanish authorities -- - from the government to the courts to the police -- have tried to choke off support for ETA in recent years , with numerous arrests of ETA suspects , convictions at trial , restrictions on political activities of known ETA supporters and a clampdown on clandestine ETA financing . The Supreme Court 's chief justice , Francisco Hernando , told reporters Wednesday that in addition to outlawing Basque Nationalist Action , the court would also immediately consider a similar ban on another leftist party , the Communist Party for Basque Lands , or PCTV as it is known locally , also for suspected links to ETA , the court 's press office said . The PCTV holds seats in the Basque regional parliament , and it activities were also suspended last February by a lower court judge . In March 2006 , ETA declared a `` permanent '' unilateral cease-fire , raising hopes for an end to nearly 40 years of ETA violence . But an ETA bomb at Madrid 's airport in December 2006 killed two men and caused heavy damage , and the Socialist government immediately ended the fledgling peace process . Yet ETA did not officially end its cease-fire until June 2007 . There are about 500 ETA convicts or suspects in Spanish jails and more than 100 more in French jails , authorities said .
Spain 's Supreme Court bans leftist party for links to Basque separatists . . Unexploded bomb later found on national police officer 's private residence in Bilbao . Was blamed for more than 100 deaths in long struggle for Basque independence .