The Taoiseach says an amnesty for crimes during the Troubles would be challenged in the courts for many years.
It comes ahead of Micheál Martin's meeting with victims' families in Dublin tomorrow.
They're campaigning against the British government's plan to ban all prosecutions relating to the Northern conflict.
The Taoiseach says he's strongly against the proposal.
"The United Kingdom proposals cannot be the basis of a way forward.
"To completely close off the avenue for justice for families is not only deeply unfair, it would also undermine the rule of law and our shared work for deeper reconciliation.
"It would likely result in years of legal challenge, and further hardship for families.
"Each family deserves access to a process of justice, and until that process is in place, families and communities will campaign."
