Two years after ETA disbanded, Spain's government is accelerating moves to transfer jailed Basque separatist militants to prisons closer to home, angering families whose lives were shattered by their violence.

The Basque separatist group waged a decades-long campaign for independence involving bombings and shootings that killed more than 850 people, with a total of 197 ETA prisoners held in prisons across Spain.

Since the 1980s, Spanish government policy has been to keep most prisoners in jails hundreds of kilometres away from the northern Basque Country region -- and separated from each other to prevent them from working together behind bars.

But prisoner support groups say this so-called "dispersion policy" is motivated by a thirst for vengeance and have lobbied for years to move them closer to their families.

Since Socialist Prime Minister Pedro Sanchez came to power in June 2018 a month after ETA disbanded, 73 prisoners have been moved to jails in the Basque Country or nearby, including some who were serving time 900 kilometres (550 miles) away in southern Andalusia, government sources say.

And the transfers have picked up in recent weeks.

Sanchez's leftwing minority government, which depends on support from Basque pro-independence party Bildu and other regional formations to pass legislation, says it is complying with the legal requirements of the prison system, which works towards prisoners' reintegration back into society.

Government sources point out that between 1996 and 2004, a total of 426 prisoners were moved closer to the Basque region by a conservative government which at the time was holding talks with ETA.

But the issue has become a hot potato in recent days after Bildu agreed to back Sanchez's draft 2021 budget in response to the government's "receptiveness" about the party's concerns.

Only a handful of ETA prisoners still support violence, and those who have been transferred or granted parole have disassociated themselves in writing from the former militant group.

"For the prisoner, being transferred is not a perk, it's a right," said Urtzi Errazkin of Etxerat, which represents prisoners' families, telling AFP the pace of transfers was "still insufficient".

Relatives of Basque prisoners hold regular protests like these to demand they be moved closer to home
Relatives of Basque prisoners hold regular protests like these to demand they be moved closer to home AFP / ANDER GILLENEA

Relatives often travel hundreds of kilometres to visit their loved ones in jail, he said.

Some of those who lost loved ones to the ETA violence also back the prisoner transfer move but the main victims' associations are fiercely opposed.

"The dispersion policy should be kept in place" because distancing prisoners from the environment where they became radicalised "is an efficient tool for achieving reintegration," said Carmen Ladron de Guevara, a lawyer for the Association of Victims of Terrorism (AVT).

AVT is currently involved in 170 lawsuits over unsolved ETA crimes and believes the government should "raise the bar" and not transfer any prisoners who don't cooperate with investigations, she added.

Government sources acknowledge that the authorities do not "demand as much information" from ETA prisoners as they did when the outfit was still active.

But remarks by Bildu's leader Arnaldo Otegi about the government's apparent openness to the party's concerns, including prison policy, have sparked political outrage, even among some of Sanchez's Socialists.

Bildu is seen as the heir to Batasuna, a Basque pro-independence party which was banned in 2003 for being ETA's political wing.

Otegi is a former ETA member who spent time in prison for kidnapping a businessman but was later credited with helping persuade the group to disband, prompting some to call him the "Basque Gerry Adams."

The Covite victims' association immediately accused the government of rolling out a "red carpet" for "ETA ideologists and those politicians who defend terrorists".

Otegi's remarks also angered the conservative opposition, which accused the government of buying votes with the prison transfers.

But it also infuriated some of Sanchez's Socialists, with Guillermo Fernandez-Vara, leader of the southwestern Extremadura region, saying he needed to "get down to the pharmacy to buy an anti-emetic" -- a drug used to prevent nausea and vomiting.