"When I was elected, I ordered a survey of the people," he says. "The overwhelming majority asked for services in their mother tongues, which were 72 percent Kurdish, 24 percent Turkish and two percent Arabic. Consequently, I ordered that all information about training and services be made available in those languages. But, the Interior Minister said this was illegal as Turkish is the only official language. I was removed from office and the authorities have started 20 cases against me for publications in Kurdish."
Despite his dismissal, many people interviewed in his office say he's still their mayor.
Chatting over strong tea in traditional bell-shaped glasses, the men said to understand the importance of Demirtas's work, one would have to speak with their mothers.
Z. Corun, 70, speaks little Turkish. She grew up in a village at a time when girls didn't go to school. She and her family were forced to move to Diyarbakir 15 years ago when their village was destroyed in fighting between the Turkish army and Kurdish separatists. Corun says leaving the countryside for city life was brutal. But Demirtas's initiatives changed her life, but only briefly.
"I was so happy when the mayor introduced Kurdish services," she says. "Until then, everything official was in Turkish. When I needed to get help for my sick husband I was always afraid they would make fun of me trying to speak Turkish. This is humiliating at my age. But with our mayor it was different. Officials greeted you in Kurdish. All information was in our language. It changed my life. But when there is a good mayor who does something for the people, the state always gets rid of him."
Some steps have been taken to loosen the controls over the use of the Kurdish language. As Turkey tries to enter the European Union, Prime Minister Recep Tayyip Erdogan announced Kurdish broadcasting is to be extended to 24 hours.
However, this government, like its predecessors, remains strongly opposed to the official use of Kurdish.
Professor of Politics Kemal Kirisci of Istanbul's Bosphorus University says such opposition is based on the fear the country could disintegrate.
"Who is really Turk in the ethnic sense of the word? When you scratch the surface of a Turk, under it you very quickly find many whose descendants are Bosnians, are Tartars, are Turks from the Balkans, Pomaks, maybe Arabs in the southeast, Kurds certainly. Such a social composition does generate concerns amongst officials and some of the public that if one group is given special status, then the next step will be others seeking it too," he said.
Demirtas is back in his office working hard to help former constituents, who still come to him. He's also preparing to run again in next year's mayor election.
"I met with a London mayor and asked him is if it's a crime to produce information in languages other than English. He said it's a crime not to. What's normal around the world is illegal here. But I believe the strength of any society is its diversity," he says.
"It breaks my heart," he continues, "that all my life, I've been told that I am a Turk and my mother tongue is Turkish. To deny this, he says means being called a terrorist, something he does not accept. The country must embrace its diversity which he says, is Turkey's strength and not its weakness."
Balancing the fear that greater cultural rights could ultimately lead to the disintegration of the Turkish state versus Kurdish demands for full recognition of their cultural identity, is the conundrum faced by all Turkish governments since the formation of the republic 85 years ago. Experts say until that balance is found, permanent peace in the predominantly Kurdish southeast will continue to remain illusive.