Belfast priest Fr Alex Reid was involved in getting Basque separatist group Eta to call a permanent ceasefire, it has been confirmed.
Fr Alex Reid said Eta had been influenced by the Irish process
The group will begin the ceasefire on Friday "to start a new democratic process in the Basque country".
Fr Reid, who was a witness to IRA decommissioning in Northern Ireland, said they were influenced by the peace process in the province.
He said they had taken "courage and inspiration" from the NI peace process.
"They would say to me here 'we had no hope'," he said.
"The people were in a hole, were in despair, and they would look to Ireland and they see what Ireland was able to do and that lifts them and kind of tells them that 'if they can do it, because their conflict is very old and very difficult, we can do it'."
Eta is blamed for killing more than 800 people in its four-decade fight for independence for the Basque region of northern Spain and south-west France.
Eta said the ceasefire would start on Friday
Spanish PM Jose Luis Rodriguez Zapatero said the government was cautious but hopeful about the announcement.
Eta, which is classed as a terrorist group by the US and the European Union, declared an indefinite ceasefire in 1998 but peace talks broke down and the bombing campaign resumed a year later.
The group has never previously called a permanent stop to the violence.
Sinn Fein President Gerry Adams said his party had been in contact with Basque political parties and that the opportunity should be grasped.
"There is a particular onus and responsibility on the Spanish government to respond positively and creatively," he said.
"The Spanish government should immediately intervene to stop the political trials against Batasuna leaders."
Fr Reid outlined what sort of concessions Eta and its political wing Batasuna may have received from the Spanish government in return for ending the armed campaign.
"One of them would be how you are going to arrange with the prisoners," he said.
"There's the legalisation of Batasuna - there must be some arrangement about that.
"They would have to do directly with Eta, and mostly with their prisoners.
"Obviously that has been worked out, I can't see them stopping unless there is a satisfactory solution."