ISTANBUL - Turkish President Recep Tayyip Erdogan's project to provide an alternative route to the Bosporus waterway is becoming increasingly mired in controversy.
Erdogan is presenting his "Canal Istanbul" initiative as preserving Istanbul, but environmental and financial concerns are escalating over the grandiose scheme, dubbed as the construction project of the decade.
In freezing rain, thousands of people in Istanbul queued for hours to sign a petition protesting Erdogan's canal plan.
"Channel Istanbul means the destruction of the 8,000-year-old history of Istanbul," said Suna Ustun, who said she waited four hours to register her opposition.
"It will eliminate all the city's natural water resources and already existing dams," she adds. "The huge amount of money allocated for this could be better spent on the economy, on the unemployed and education."
But Erdogan, who has even called his project "crazy," is hitting back with glitzy promotional videos that have been blitzing the media to promote the $12-billion project.
The videos highlight plans for a new city and towns on the banks of the massive sea-level channel that would provide an alternative route for ships.
"Istanbul's Bosporus is under constant threat of accidents as well as the separate political threat of the Montreux Convention," said Erdogan earlier this month at an Istanbul meeting promoting the scheme.
"Whether they want it or not, we will build Channel Istanbul!" he declared.
The 1936 Montreux treaty regulates the transit of all ships through the Bosphorus.
The straits are one of the busiest waterways in the world, used by some of the world's largest supertankers, carrying their hazardous loads just meters from the shore.
Accidents do happen, and in December, a cargo ship's steering locked and it crashed into the shore, shocking pedestrians walking on the waterfront.
"A tanker accident in 1979 [in Istanbul], tens of people lost their lives, and 100,000 tonnes of oil spread to the sea and destroyed the sea life," said Professor of Civil Engineering Mustafa Ilicali, who is a former deputy of the ruling AKP.
"There can be such an accident at any moment because of the narrow angle of turns [on the Bosporus], which are made more difficult by the strength of wind and currents, which flow both ways, and we have heavy local sea traffic."
"Today's number of ships using the Bosporus is 40,000 annually. But the actual capacity of the straits is 25,000. What will happen when it rises to 75,000," he added.
Yet environmentalists warn that building a canal could destroy local water supplies and the regional ecosystem when the canal connects Marmara and Black seas, which have different salinity levels.
Istanbul's newly elected mayor, Ekrem Imamoglu, already touted as a potential challenger to Erdogan's presidency, is leading the campaign against the canal.
Imamoglu slams the canal project as both an environmental and financial disaster, claiming the real cost will be more than $75 billion.
Some analysts say a battle of wills is looming between the two political heavyweights, and the significance will extend beyond the canal project..
Transport Minister Cahit Turhan countered, claiming Monday that annual transit fees of up to a billion dollars will cover the cost of the canal.
Analysts point out, however, it's unlikely ships will pay when the Bosphorus is free — unless more significant restrictions on the use of the straits were imposed by Ankara, which likely would be considered violations of the Montreux Convention.
Experts also warn Erdogan's canal plans are likely to face growing international push-back because of fears the project could undermine the Montreux Treaty.
"For us, it [Channel Istanbul] is an artificial waterway that we are creating. This is a separate situation from Montreux regulations for the [Bosporus] Straits and for the Channel would be different,” said Ilicali
It has been predicted by some that such a statement will cause alarm in Moscow.
"The Montreux Convention is of the utmost importance for them. It's a sacred cow for Russia," said former Turkish Ambassador Mithat Rende, an expert on the Convention.
The treaty strictly controls the use of the Bosphorus by warships of non-Black Sea countries, limiting the presence of the U.S. Navy in the Black Sea.
"The Russians are aware the Americans feel uneasy about the Montreux Convention," Rende added. "Because they have limited access to the Black Sea, because of the limited tonnage that each country cannot keep more 30,000 tonnes of capacity in the Black Sea for a period of 21 days only. That is a burden to America, with the situation in places like the Ukraine and Georgia."
Erdogan frequently alludes to unnamed security and strategic advantages offered by the canal. It's a reference some experts assert is an opportunity for Ankara to control the access of warships to the Black Sea.
Old naval guns outside Istanbul's Maritime museum on the Bosporus serve as a reminder of the centuries of battles for control of this crucial waterway. A new struggle appears now to be looming over the mighty canal.