In 1968, Georkadjis offered assistance to Alekos Panagoulis, a Greek political activist (and later politician), who opposed the rise of the military junta in Greece, in his attempted assassination of dictator George Papadopoulos on 13 August 1968. Panagoulis was arrested shortly after the failure of the attempt. Why Georkadjis, a confirmed anti-communist, would conspire with the communist Panagoulis to overthrow the dictatorship in Greece, remains unknown to this day. It is not likely Georkadjis was acting out of ideology. It is much more probable that he attempted to use Panagoulis as part of some greater plan, since there were growing signs of disagreement between the government of Cyprus under President and Archbishop Makarios and the military junta in Greece. What is known is that Georkadjis simultaneously attempted to ship explosives and weapons to Greece using diplomatic bag prerogatives.
Despite the torture he was subjected to, Panagoulis revealed nothing. However, the Georgadjis connection became known to the junta and Archbishop Makarios, President of the Republic of Cyprus, was forced by the junta to ask for Georkadjis' resignation. The dictator Georgios Papadopoulos, the target of the attempt, had been godfather at the baptism of Georkadjis' first child, Constantinos, just a year earlier, which particularly incensed Papadopoulos.
In 1970, juntist Greek officers of the National Guard in Cyprus planned a coup against Makarios (Operation Hermes). They approached Georkadjis, who was still sidelined after his resignation, but continued to command a deep network inside the state, and the police force in particular. They asked him to plan and execute the assassination of Makarios which was intended to spark off unrest, so that the National Guard could then intervene and "restore order". Georkadjis agreed to co-operate.
Georkadjis' men shot at Makarios' helicopter just after it took off from the Archbishopric in Nicosia to convey the Archbishop to a memorial service for EOKA hero Grigoris Afxentiou in the mountains of Macheras. The machine was damaged and the pilot wounded, but a successful forced landing was made nearby and Makarios escaped, taking the pilot to Nicosia General Hospital with the aid of passers-by. The plan failed and the role of Greek officers Poulitsas and Papapostolou, who were part of Makarios' entourage, was revealed. Georkadjis attempted to appease Makarios by leaking the plan for Operation Hermes to Speaker of the House of Representatives Glafkos Klerides, who forwarded it to Makarios. Makarios did not need to see the plan to know that the Greek officers in the National Guard and the junta of Athens were behind the attempt. He also did not want to escalate the crisis in his relations with the junta. Via selective leaks to the press from the Presidential Palace, the plan for Operation Hermes was exposed publicly, but denounced as a fake designed to shatter the confidence of the people in the National Guard. Makarios publicly stated his confidence in the National Guard to defuse the crisis, temporarily at least.
A week later, Georkadjis drove to a secret night rendezvous in an open area outside the village of Mia Milia. He asked a close associate to accompany him, but dropped him off some distance from the meeting point and drove on alone. As Georkadjis' car approached another car parked at the meeting point, the occupants of the other car opened fire with automatic weapons. One of them then walked up to Georkadjis' car and delivered a coup de grâce. They then drove off leaving Georkadjis dead at the scene. Fanis Demetriou, the police officer in charge of the investigation quickly found evidence pointing towards the same two Greek officers in Makarios' entourage who had been found to be involved in the Hermes plot. After he reported this to his superiors, Demetriou was ordered off the case. The two particular Greek officers were eventually only questioned several weeks later, at which time they gave identical accounts of their whereabouts on the night of the murder. They both left the island shortly thereafter and never returned.
In the trial of the men in the teams that shot at the President's helicopter, the court noted the leading part Georkadjis played as chief instigator and planner of the attempt, but did not call him to account as he was already deceased.
Georkadjis' widow Fotini married Tassos Papadopoulos, then Minister of Labour, within months of her husband's death. Papadopoulos and Georkadjis had been close friends, and Papadopoulos had been best man at Georkadjis' wedding.
Though Georkadjis planned and executed an operation to assassinate the President of the Republic, and though his role in this has been acknowledged by the courts, the yearly church service in his memory is attended by prominent figures among the Greek Cypriot political leadership and at least one street has been named after him. A museum honoring the most distinguished aspects of his life is active in his birthplace in Palaichori, formally opened in 2002 by the then President Glafkos Clerides.