Yiğit Aksakoğlu has been in jail in Turkey for four months. He and twelve others were imprisoned last November, awaiting trial on charges of ‘attempting to overthrow the government’ during the Gezi Park protests six years ago.

The other twelve have been released, but Yiğit – pronounced ‘Yeet’ – remains in the maximum security Silivri prison, west of Istanbul. He is held alongside Osman Kavala, now in his second year of arbitrary detention, and 14 others whom the Erdoğan government accuses of insurrectionary ambitions in a 600-page document of which only a few pages, lawyers say, have any legal significance.

For those of us who know Yiğit, the charges against him make no sense. He ran the Turkey programme of the Bernard van Leer Foundation, a Dutch organisation that invests in early childhood development. His wife, Ünzile, is left trying to explain what has happened to their seven-year-old daughter. His 70-year-old mother, who raised Yiğit and his sister Ece without their father, makes a monthly journey across Turkey for the single visiting hour that her son is permitted.

His requests for a cell mate, to end his solitary confinement, have been denied. A triathlete in a former life, he has been allowed outside to run in the yard, but only twice. He skips rope using the short line on which the laundry he washes in his cell also hangs to dry. Books are heavily vetted. His mother brought him a television set which he has been allowed in his cell. At the third time of asking, he was allowed his ukulele.

In April 2015, an Istanbul Court ruled that the Gezi protests were legal under the European Convention on Human Rights – to which Turkey is a signatory – as well as Article 34 of the Turkish Constitution, which guarantees the freedom to peaceful assembly. At its brightest, Gezi was an appeal to a democratic Turkey of many peoples, religious and secular, Turks, Kurds, Armenians, Alevi and others, a reflection of the ‘neo-Ottoman era’ that Erdoğan is so fond of invoking. In some ways all this is relevant; in other ways it isn’t: Yiğit scarcely attended a meeting.

At one point the 600-page dossier features a photo taken on a phone, showing regional maps of bee colonies, which the state has cited as evidence of intent to redraw borders across the Middle East. Plans discussed at a meeting to provide food – pastries, milk, juice – for people at the Gezi protests are being represented as a sophisticated logistical operation and part of a sinister plot.

If only such plans were in place for Turkey’s prison system, which is straining under the weight of the recent purges. At Silivri, prisoners are allowed to buy themselves occasional fruit and vegetables, but only if they make a written request, and as long as their families keep their prison accounts replenished with funds. Since the 2016 coup attempt, 200,000 public sector employees have been dismissed from their posts. The government has announced plans to build 193 new jails in the next five years, to accommodate a population estimated at nearly 250,000, and 40,000 over capacity.

The Gezi protests achieved their primary aim: the park has not been developed into a shopping mall; it is still an open, green public space. Large demonstrations can still take place in Turkey, but they have to be authorised and are often funnelled towards out-of-town spaces. The political climate also leaves such protests reliant on official opposition parties. Grassroots mobilisations are beginning to reappear, and a theatre company recently went against official instructions by marking World Theatre Day in Istanbul’s Kadiköy neighbourhood, but a movement on the scale of Gezi is unthinkable.

The incarceration figures measure two things: the authoritarianism of the government, but also Turkish society’s will to freedom. A concerted effort on behalf of the group initially detained with Yiğit saw them quickly let go. Civil society has won other important battles, securing the release of the investigative journalist Ahmet Şık, who is now a member of parliament with the People’s Democratic Party (HDP). Amnesty International’s Turkey chair, Taner Kılıç, was last year freed after eight months in jail.

Opposition to the government has also been expressed at the ballot box, with the AKP suffering defeat in local elections in Ankara and probably Istanbul, too. The results don’t substantially change much, however, and Erdoğan met them with magnanimity, saying that ‘every gain and every loss is the will of our people and also a requirement of democracy that should be acknowledged.’

Yiğit’s detention is going to be reviewed tomorrow. Amnesty has been asking people to write to the justice minister, Abdülhamit Gül, to demand his release.