Dublin City Council is due to host a civic reception at the Mansion House tonight for the family of murdered Belfast man Robert McCartney.
The 33-year-old father-of-two was beaten and stabbed to death in Belfast on January 30, allegedly by senior IRA members.
His sisters and fiancee have responded to the killing by mounting a campaign against the republican movement, which they accuse of covering up the crime.
Speaking ahead of this evening's reaction, Dublin Lord Mayor Michael Conaghan said he believed their cause was a fundamental human rights issue for everyone in Ireland.
"What they have done is quite unique," he said. "They have simply not accepted this injustice that's been visited upon them, they have stood up against very substantial odds and I think people have rallied to them."