Top Turkish officials on Sunday lashed out at an open letter signed by more than 100 retired admirals warning about a possible threat to a treaty governing the use of Turkey's key waterways, AFP reported.
Turkey's approval last month of plans to develop a shipping canal in Istanbul comparable to the Panama or Suez canals has opened up debate about the 1936 Montreux Convention.
Canal Istanbul is the most ambitious of what President Recep Tayyip Erdogan terms his "crazy projects," which have seen him transform Turkey's infrastructure with new airports, bridges, roads and tunnels during his 18 years in power.
Turkish officials argue that the new canal is vital to take the pressure off Istanbul's Bosphorus Strait.
But opponents say apart from its environmental impact, the new canal venture could undermine the Montreux accord.
The convention guarantees the free passage through the Bosphorus and Dardanelles straits of civilian vessels in times of both peace and war.
It also regulates the use of the strait by military vessels from non-Black Sea states.
The new canal would allow ships to transit between the Mediterranean and the Black Sea without passing through part of the straits that are covered by the treaty.
In their letter, 103 retired admirals said it was "worrying" to open the Montreux treaty up to debate, calling it an agreement that "best protects Turkish interests."
"We are of the opinion to refrain from any kind of rhetoric or action that could make the Montreux Convention... a matter of controversy," they said.
The letter drew a strong riposte from top government officials, while prosecutors in Ankara have also launched an investigation.
"Not only those who signed but also those who encourage them will give an account before justice," Erdogan's top press aide Fahrettin Altun said on Twitter, referring to the probe.
Presidential spokesman Ibrahim Kalin said the declaration was "reminiscent of coup times".
Istanbul mayor Ekrem Imamoglu of the opposition CHP party is one of the strongest opponents of the canal project on financial and environmental grounds.
In November, the interior ministry launched a probe into the mayor over his opposition to the canal.
