Prominent dissident republican Colin Duffy is set to go to the Supreme Court over being denied assurances his legal consultations were not bugged.
Senior judges in Belfast ruled last month that they have no jurisdiction to hear his challenge to the failure to confirm no covert surveillance took place.
They instead held that exclusive authority for determining the issue rests with the Investigatory Powers Tribunal sitting in London.
Returning to the case on Wednesday, the same judicial panel formally refused leave to mount a Supreme Court appeal against their verdict.
However, they did certify a point of law of general public importance relating to the activities of the intelligence services.
That permits Duffy’s lawyers to seek a hearing at the Supreme Court.
The dissident republican, from Forest Glade in Lurgan, Co Armagh, wants to judicially review the British Government for allegedly refusing to provide guarantees that the security services did not bug his meetings with lawyers.
He is one of three men facing trial on charges of belonging to an IRA grouping, and attempting to murder members of the PSNI.
They face further counts of possessing firearms and ammunition, and conspiracy to murder security force members.
The alleged offences are connected to a gun attack on a police convoy in the north of the city.
A PSNI Land Rover and two accompanying vehicles came under fire on the Crumlin Road in December 2013.
Duffy is charged along with 54-year-old Alex McCrory, from Sliabh Dubh View in Belfast; and 47-year-old Henry Fitzsimons, of no fixed address.
Separate legal proceedings were launched in an effort to gain assurances that the security services were not listening in to Duffy’s legal consultations.
He was said to have received satisfactory assurances from the Prison Service, Courts and Tribunal Service and the National Crime Agency.
But no such guarantee was given by the Home Office.
High Court proceedings were lodged in a bid to have the failure to provide that assurance quashed and declared incompatible with Duffy’s human rights.
However, a panel of three senior judges had to first determine if they had authority to deal with the case, or if the issues should go before the Investigatory Powers Tribunal set up to monitor surveillance authorised under the 2000 Regulation of Investigatory Powers Act (RIPA).
The tribunal sits as an independent court to decide on allegations of unlawful intrusion by public bodies and claims under the Human Rights Act.
According to the High Court judges sole jurisdiction lies with the tribunal.
Now, however, a further appeal is expected.