CHP leader Kemal Kilicdaroglu launched the long march on Thursday after Enis Berberoglu was sentenced to 25 years in jail for allegedly disclosing confidential information involving National Intelligence Organization (MIT) trucks going to Syria in January 2014.
Addressing a Turkish Exporters Assembly meeting in Istanbul, Erdogan said: "Calling on citizens to take to the streets by disregarding the constitution is neither for their own good nor for the good of the country."
The president said marching with banners reading 'justice' would not bring justice. "If the judiciary is under such pressure, how can we expect justice? If you are seeking justice, then the parliament is the place," he said.
Erdogan added Kilicdaroglu clearly violated Article 138 of the Constitution, which states that no organ, authority, office or individual might give orders or instructions to courts or judges relating to the exercise of judicial power, send them circulars, or make recommendations or suggestions.
"Article 138 does not just apply to politicians. It applies to everyone from A to Z, so don't be surprised if you are invited to some place by the judiciary tomorrow," he warned, calling on everyone, including non-governmental organizations, to respect the separation of powers, without which, he said "we cannot get anywhere".
Berberoglu was accused of leaking footage of the MIT trucks to Can Dundar, the then editor-in-chief of Cumhuriyet daily. The footage showed MIT trucks being stopped by local gendarmerie in the southern province of Adana despite a national security law forbidding such a search.
The Interior Ministry later denied media reports the trucks were carrying arms to groups in northern Syria, saying that in fact they were transporting humanitarian aid to the Turkmen community in the war-torn country.