As a child, Dominic Og McGlinchey witnessed both the murder of his mother Mary in Dundalk in 1987 and his father Dominic in Drogheda in 1994. Nobody has been convicted in connection with either killing.

Lawyers for Mr McGlinchey allege that neither attack was properly investigated by the State in line with its human rights obligations.

Ms Justice Niamh Hyland granted leave at a sitting of the High Court yesterday, in which Ronan Munro SC appeared with Glenn Lynch BL and Conan Fegan BL on behalf of Mr McGlinchey.

Mulholland Law, representing Mr McGlinchey, said in a statement: “Today’s decision marks a significant step towards seeking clarity and accountability from the State.

“It is indeed an outrage that the family was compelled to pursue litigation without any prior progress being offered by the State in response to their pleas for engagement.

“The manner in which victims and survivors of the Troubles are dealt with in this State needs addressed whereby a compassionate approach within the spirit of the Good Friday Agreement is adopted.”