A nine-week trial at the High Court in Glasgow ended with convictions for Antoin Duffy, 39, his cousin Martin Hughes, 36, and Paul Sands, 32.

They were conspiring to murder Johnny “Mad Dog” Adair and Sam McCrory, best friends who were leading members of the UDA and the Ulster Freedom Fighters (UFF). Both men played an important role in securing support for the Good Friday Agreement among loyalist prisoners.

Duffy and Hughes were also convicted of terrorism charges.

The police operation which led to their arrests also led to the apprehension of Craig Convery and Gordon Brown, who have been found guilty of organised crime charges.

Judge Lady Scott has deferred sentence on all five men until August. She also ordered background reports on the five men and a psychiatric report on Duffy.

She reportedly told the jury they would be excused from returning to jury service for life, telling jurors: “The court is enormously grateful to you. You have dealt with a particularly difficult case involving really serious charges.”

Detective Superintendent Andy Gunn, head of Police Scotland’s Organised Crime Unit in Glasgow, said: “Antoin Duffy was the main instigator of the plot to kill two men, due to his twisted ideology to further the aims of dissident republican terrorism.

“He is a dangerous man who was determined to see this conspiracy through to its conclusion.

“I have no doubt that were it not for the intervention of the authorities in an operation led by Police Scotland, we would have been left investigating a double murder in an act of terrorism carried out in our communities.”