Greece is pressing ahead with plans to resume seabed surveys for the Cyprus-Crete electricity cable, while Turkey insists it must be consulted as a “coastal state” before any work takes place.

The company running the project, known as the Great Sea Interconnector (GSI), is finishing its technical preparations. It is in talks with the Greek government on when to submit a formal request to authorise the survey vessel and have a NAVTEX, a maritime notice to shipping, issued. Athens says the project will go ahead and the notice will be published as soon as the request arrives.

About 60 per cent of the surveys have been completed, according to Admie, Greece’s power grid operator, which owned the project before its French majority shareholder took over. The remaining 40 per cent lie in waters claimed by both Greece and Turkey. Greek Foreign Minister Giorgos Gerapetritis has said it would be “inconceivable” for Turkey to obstruct the work. The cable has EU status as a project of common interest and has received a €657 million grant from the European Commission.

Several days of recycled reports in the Greek and Turkish press had muddied the picture and left Ankara with the impression that Athens might change the cable’s route. On Thursday, Turkey’s defence ministry stepped in to restate a position that, it says, has not changed since 2024, when Turkish warships were deployed after an Italian-flagged survey vessel entered waters Ankara considers its own, near the Greek island of Kasos. It said this held despite any misreading by well-meaning observers on all sides.

The ministry repeated that any cable or pipeline laying, and any scientific research, on what it calls the “Turkish continental shelf” must be coordinated with Turkey as the coastal state. It warned that it would not allow any unauthorised activity there. Turkey set out the limits of that shelf unilaterally in a letter lodged with the United Nations on 18 March 2020, the first official depiction on a map of its “Blue Homeland” doctrine of maritime claims.

The statement severely limits efforts being made behind the scenes to find a formula for resuming surveys east of Kasos and as far as Cyprus. Any such arrangement would have to protect Greek sovereign rights in full while avoiding a Turkish reaction that would inevitably spark a crisis.

A major dispute

The survey and laying of the cable has now become a central point of Greek-Turkish confrontation. For Greece, it is a question of exercising sovereign rights in a lawfully delimited exclusive economic zone (EEZ) and over its continental shelf. For Turkey, it is a chance to assert its position on the ground and lend legitimacy to the 2019 Turkey-Libya maritime memorandum, which underpins the Blue Homeland doctrine and which Greece regards as null and void.

By demanding a say as a coastal state, Ankara has also ruled out an option that had been reported in recent days. Under it, Greece would have notified all eastern Mediterranean states of the surveys instead of asking Turkey for permission. French officials were reportedly pursuing this idea in contacts with Ankara.

The alternative had weaknesses from the outset. Other states are informed of surveys through a NAVTEX issued by the coastal state. Under standard practice, a notification includes a full file on the vessel, its characteristics, its route and other technical details. It goes to the coastal state that exercises sovereign rights over the waters in question, and that state is also responsible for issuing the NAVTEX.

Athens cannot accept this kind of “notification-cum-permission request” to the Turkish authorities. It would amount to formal, if indirect, acceptance of the Turkey-Libya memorandum, would cancel Greece’s delimited EEZ and would recognise a form of joint management of the areas concerned.

Greek officials also regard the debate over rerouting the cable as unhelpful. The idea was to avoid a marine park that Turkey recently established, but it sent Ankara the message that Greece was looking for a way to back down under pressure. There was no reason for the change in the first place, as the original route passes dozens of miles south of the park.

More importantly, Turkey’s objections go well beyond the park. Thursday’s statement made clear that its “ban” covers the entire area that Athens says Turkey has illegally delimited as its own EEZ and continental shelf. On the map Turkey filed with the UN, that area begins at the outer limit of the six-nautical-mile territorial waters around Greek islands.

Even a new route would therefore not solve the problem. It would also raise questions over the viability of the project because of the higher cost of redesigning it.

A show of strength

Turkey has again chosen Cyprus for a show of force. It is responding to moves by Nicosia to strengthen its alliance with Israel and to advance energy plans, including the development of the Glaucus gas field by ExxonMobil.

Following surveys that began in July, Turkey issued a fresh NAVTEX for the Oruc Reis research vessel to begin work in the area between Turkey and Turkish-occupied northern Cyprus, ahead of the laying of a natural gas pipeline.

Athens was quick to condemn the move in a statement from diplomatic sources. They said unilateral action to develop energy infrastructure without the consent of the Republic of Cyprus has no basis in international law or the UN Convention on the Law of the Sea (UNCLOS) and violates Cypriot sovereignty and sovereign rights. They added that such actions form part of a continuing effort to entrench the “fait accompli” of the occupation and clearly contravene the rules of international law.

Athens is sending the message that breaches of international legality and challenges to sovereign rights are a widespread Turkish practice under the Blue Homeland doctrine. In its view, they concern far more than Greece and destabilise the whole of the eastern Mediterranean.