The Taoiseach, Micheál Martin TD said he was "disappointed" that the British government has not committed to holding a public inquiry into the murder of Belfast solicitor Pat Finucane, as agreed between the British and Irish governments in 2001.
In a statement this evening, the Taoiseach met with Pat’s widow, Geraldine Finucane, and her son John last week.
Following their meeting, he said he wrote to British Prime Minister Johnson about the case.
He also spoke with the British Prime Minister by phone last Friday, to set out to him directly the compelling case for holding a public inquiry.
Mr Martin said today's decision would "come as a further blow to Geraldine and her family, who have been pursuing truth and justice for three decades with great dignity."
However, the Taoiseach noted that the Secretary of State for Northern Ireland did not rule out a public inquiry taking place in the future.
He added that the Government would "reflect on the steps outlined by the British government today, but that it remained strongly of the view that a public inquiry was needed."
"Dealing more broadly with legacy issues from the Past was a shared challenge," he said.
"In this context, delivering on prior commitments, however difficult, was important in terms of building public confidence and trust."
The British Government ruled out a public inquiry into the murder of Belfast solicitor Pat Finucane earlier this evening.
Britain's Northern Ireland Secretary of State Brandon Lewis said he had decided not to establish an inquiry but that the British Government remained committed to the process of reconciliation.
Speaking earlier, Mr Lewis said: "I have today spoken to the Finucane family. I advised them of my decision not to establish a public inquiry at this time."
For their part, Mr Finucane's family called the British Government's decision "Astonishing, arrogant and cruel."
Mr Finucane, a 39-year-old solicitor who represented both republican and loyalist paramilitaries during the Troubles, was shot dead in his family home in north Belfast in February 1989 by the Ulster Defence Association in an attack found to have involved collusion with the state.