The move comes after the EPPK, a collective representing hundreds of jailed ETA members, in December dropped its longstanding demand for a general amnesty and said it would let jailed ETA members negotiate individually for their release.

The treatment of jailed ETA convicts is one of the most delicate issues in a standoff between the authorities and western Europe’s last major armed secessionist movement.

“Bringing Basque prisoners to Euskal Herria would give an incredible boost to the peace process,” EPPK representative Marixol Iparragirre told Basque newspaper Gara, using the Basque language name for the Basque Country.

“To speed up the peace process it is essential and urgent to end the dispersion of prisoners and find an immediate solution to the most serious situations so that our voices, both inside and outside of jail, can be heard normally,” she added.

The group will also request that seriously ill ETA prisoners and those over the age of 70 be released from jail, said Iparragirre, who was sentenced by a French court in 2010 to 20 years in prison for financing terrorism.

Spain has for decades dispersed ETA prisoners across the country, in part to prevent convicted Basque militants from communicating easily among themselves.

A committee supporting the prisoners, Etxerat, says 520 prisoners remain affiliated to ETA, most of them spread across 79 jails in Spain and France.

ETA prisoners in Spanish jails will ask to be transferred to the Zaballa prison in the Basque province of Alava, while those in French jails will request being “regrouped in the prison closest to home”, Iparragirre said in the joint interview with another EPPK representative, Jon Olarra.

ETA, blamed for the deaths of 829 people in a four-decade campaign of shootings and bombings for an independent homeland in northern Spain and southern France, renounced its armed struggle in October 2011.

In a statement sent earlier this month to Gara, its usual mouthpiece for announcements, ETA said it plans to make “significant contributions” towards a lasting settlement to its armed independence campaign “without delay”.

The governments of Spain and France refuse to negotiate with ETA, which is classed as a terrorist organisation by the European Union and the United States.