The British House of Lords is to be asked to decide whether the re-election of Mr David Trimble as Northern Ireland First Minister last November was valid.
The Democratic Unionist Party is to present their case against the validity of Mr David Trimble as Northern Ireland First Minister last November to the British House of Lords.
The DUP brought its challenge to the election of Mr Trimble, and Mr Mark Durkan as Deputy First Minister, to the courts in Belfast.
In a judgment today three Appeal Court judges voted two to one in rejecting the challenge to the elections which took place outside a designated time frame, and to the decision of Northern Ireland Secretary Dr John Reid not to call fresh Assembly elections before May next year despite the lateness of the election.
However the dissenting voice was that of the Northern Ireland Lord Chief Justice, Sir Robert Carswell, and the DUP said they were using his argument to back their case in the Lords.
The case was taken up by DUP deputy leader |Mr Peter Robinson, who said following the judgment that Sir Robert's dissenting opinion "vindicated our decision to take legal action."
Mr Robinson said it was an "unprecedented decision" that the Lord Chief Justice delivered a dissenting judgment in his own court.
"Fortified by Lord Chief Justice Carswell's judgment on this matter we have already been granted leave to bring this matter to the House of Lords.
"Going to the House of Lords armed with the judgment of the most eminent judge in Northern Ireland has given us a significant boost."
PA