ETA convicts say recognize Spanish justice, eye sentence changes MADRID (Reuters) - Jailed members of Basque separatist group ETA said on Saturday they would recognize Spain's criminal justice system and acknowledged the pain caused by four decades of violence, in a highly symbolic move that could strengthen the peace process. ETA convicts have argued that they are political prisoners and have long rejected the terms of their imprisonment. Their shift could allow some prisoners to win early release or negotiate other demands and it opens the door to further possible concessions by the weakened group, which announced a ceasefire in 2011. "We recognize, in all sincerity, the suffering and damage caused to all parties," representatives of Basque prisoner collective EPPK, which includes ETA convicts, said in a statement sent to regional newspaper Gara. "We take entire responsibility for the consequences of our political activities," they said in the statement, written in Basque and translated into Spanish by Gara. About 600 ETA members are in prison in Spain. ETA - or Euskadi Ta Askatasuna, which means Basque Homeland and Freedom in Basque - dates back to the late 1950s and killed more than 800 people over more than four decades, many with car bombs. Speculation has recently grown that the group, gutted by hundreds of arrests and flagging political and social support in the Basque Country, could be ready to announce a full disarmament by the end of the year, although ETA has never said it would in previous statements. ETA prisoners have also long fought to see out their jail terms in the Basque Country, a process that could possibly get underway if the convicts are prepared to abide by the terms of the Spanish criminal justice system. The issue of ETA prisoners is still a very sensitive one in Spain. A ruling by the European Court of Human Rights in October freeing 60 ETA prisoners sparked outrage among Spaniards. The court said the extended detention of an ETA militant was illegal because of changes to sentencing rules that happened after her conviction, setting a precedent that helped other prisoners also walk free. Reporting by Rodrigo de Miguel, Writing by Sarah White, Editing by Gareth Jones