The Crete–Cyprus cable is now a test of notification against permission

Türkiye has restated, twice in a week, that no one may lay cable across what it regards as its continental shelf without asking first. On 24 September its defence ministry said that “under international law, activities such as laying cables or pipelines and conducting scientific research on our continental shelf must be coordinated with our country in advance.” On 1 October it added that Ankara “will not permit any unauthorized activity” there. The target is the Great Sea Interconnector (GSI), the planned power cable from Crete to Cyprus and later to Israel. Greece’s government spokesman, Pavlos Marinakis, replied that no permission is required and the project will proceed as planned. The question now is not whether the cable is legal, which each side answers differently, but what procedure will govern the next survey ship.

What has changed since 2024

The dispute is not new. In July 2024 Türkiye sent warships when the Italian-flagged survey vessel Ievoli Relume worked near the Greek islands of Kasos and Karpathos, and the surveys stopped. Angelos Syrigos, a Greek governing-party MP and international law professor, told ERTNews that Greece “backed down” twice that year, in July and November; Turkish Minute dates the second episode to a month after the first. Syrigos noted that seven cables had been laid in the region between 2003 and 2023 without similar problems.

Three things are different now. First, ownership. French infrastructure investor Meridiam bought 66 per cent of the project in August, and France’s Nexans has been chosen to lay the cable. Greek City Times reports that a French-flagged vessel is expected to carry out the remaining surveys. Second, the legal posture. Athens and Paris have agreed, according to Kathimerini as reported by Greek City Times, that Türkiye will be notified of survey work, not asked to approve it, and that France could issue a formal communiqué naming the areas and duration. Third, the Turkish response. CNN Türk reports that Ankara wants written notice from Paris; Knews, the English edition of Cyprus’s Kathimerini, reads the 1 October statement as ruling out a simple notification and insisting on authorisation.

The legal gap is real

The two positions rest on incompatible maps. Greece and Cyprus hold that islands generate their own continental shelf and exclusive economic zone under the UN Convention on the Law of the Sea. Türkiye, which is not a party to that convention, bases its claim on its 2019 maritime memorandum with Libya, which Athens considers void, and on coordinates it lodged with the UN in March 2020; its 1 October statement also cited an agreement with the Turkish Republic of Northern Cyprus, which only Ankara recognises. Greek Foreign Minister Giorgos Gerapetritis says the route passes through undelimited waters that Greece regards as its shelf, and has called Turkish obstruction “inconceivable”.

Kathimerini reported on 27 September that Athens and Paris had concluded that a “slight redesign” of the route was necessary to keep it outside the Fethiye–Kaş marine park that Türkiye declared south of Kastellorizo in August. Marinakis said he was not aware of any redesign. Even if the route moves, the marine park was only one layer of the problem. The continental shelf claim covers far more of the sea between Crete and Cyprus.

Why the procedure matters more than the route

A subsea power cable is not a single event. It needs surveys, laying, and then decades of inspection and repair, each requiring vessels to work in the same contested waters. If the first survey proceeds on notification alone, that becomes the precedent for every later repair. If it proceeds only after Turkish consent, Ankara gains a standing say over a piece of EU-funded infrastructure. That is why neither side is treating the formula as a technicality.

The stakes extend beyond the GSI. Hasan Tacoy, energy minister in the Turkish Cypriot administration, told the Cyprus Mail on 16 September that a planned Cyprus–Lebanon cable was “not possible without Turkey’s permission” either. On 1 October Türkiye issued a NAVTEX for the research vessel Oruç Reis to survey the route of a gas pipeline between Türkiye and northern Cyprus; Greek diplomatic sources, quoted by Knews, called it a provocative and unilateral move that violates Cypriot sovereign rights. Each side is now using the same tool, the maritime notice, to assert jurisdiction over the same sea.

The money is also unsettled

The political dispute sits on top of a financial one. Cyprus’s energy regulator put the cost at €1.9392bn in 2024, expecting no more than 5 per cent growth. Cyprus’s finance minister, Makis Keravnos, has said the final cost is not known and has cited estimates of €2bn to €2.5bn and €3bn, according to Cyprus Business Now. Cost-sharing gives Cyprus 63 per cent and Greece 37 per cent after the EU grant. Keravnos told parliament that the €1.9bn figure mainly covers the cable itself, and that other construction, insurance, warehousing and maintenance would raise the total significantly; the European Investment Bank is updating the viability study. Every month of standoff at sea adds to a bill that neither government has yet put a final figure on.

What to watch

• The NAVTEX for the remaining surveys east of Kasos, which Gerapetritis says Greece will issue and CNN Türk expects in November.
• Whether France sends Ankara a communiqué and how Türkiye characterises it: as notification it can live with, or as an unauthorised activity.
• US Secretary of State Marco Rubio’s visit to Athens on 6–8 October, where the cable and Greek plans to extend territorial waters south of Crete are expected to be discussed.
• Turkish naval movements around the Oruç Reis survey, which will show how Ankara links its own pipeline project to the GSI.

A compromise that lets the survey proceed without either side conceding its legal position is possible: a French notice framed as courtesy, a Turkish reply framed as acknowledgement. Such formulas have kept other eastern Mediterranean disputes cold. What has changed is that the formula must now hold for the life of a strategic asset, not for a single voyage.

Sources

• Cyprus Mail — Cyprus-Lebanon undersea cable ‘not possible without Turkey’s permission’
• Turkish Minute — Turkey says Greece-Cyprus-Israel power cable must be coordinated with Ankara
• Cyprus Inform — Greek foreign minister says Turkey cannot obstruct Great Sea Interconnector surveys
• Cyprus Mail — Greece denies reports of GSI cable route redesign
• Greek City Times — Greece and France weigh new route for Crete-Cyprus cable amid Turkish marine park dispute
• Cyprus Business Now — The GSI file: How much will it ultimately cost Cyprus?
• Greek City Times — Turkey Says Greece-Cyprus Cable Crosses Its Continental Shelf
• Greek City Times — Greece Halted Cable Surveys After Turkish Warships Appeared
• Greek City Times — Marco Rubio heads to Athens with defence, energy and Eastern Mediterranean agenda
• Knews (Kathimerini Cyprus) — Turkey demands permission for Greece-Cyprus cable, Athens says none is needed