Günal Kurşun is an Executive Board Member of the Human Rights Agenda Association.

In July 2017, Günal Kurşun was taken into custody after police raided a workshop he was attending at the Büyükada Ascot Hotel, together with other human rights organisation representatives. He was detained for 113 days and charged with "being a member of an armed terrorist organisation", "aiding armed terrorist organisations" and "committing crimes on behalf of a terrorist organisation without being a member".He is one of the defendants in the Büyükada case and was released pending trial. He faces five to ten years in prison.

He was one of the people dismissed from their positions at Adana Çukurova University’s Faculty of Law following the emergency decree issued in October 2016. Apart from the Büyükada case, also known as the ‘Istanbul 10’, there are two other cases against Kurşun. They are related to him being a member of the trade union for education Eğitim-Sen and making a press statement with them, and for writing articles for the Zaman newspaper, which was later shut down. As a result of the emergency decree, his passport was cancelled and his license to practice as a lawyer was revoked.

The cases against Kurşun are still ongoing.

Along with Günal Kurşun, the others in the Büyükada case are standing trial as well; İdil Eser (Director of Amnesty International Turkey), Nalan Erkem (Helsinki Citizens Assembly), İlknur Üstün (Women's Coalition), Veli Acu (Human Rights Agenda Association), Nejat Taştan (Association for Monitoring Equal Rights), Özlem Dalkıran (Helsinki Citizens Assembly), Şeyhmus Özbekli (Hak İnisayatifi), Taner Kılıç (Chair of Amnesty International Turkey), Peter Frank Steudtner (trainer)and Ali Garawi (trainer).

At the hearing on 27th of November, the prosecutor announced his opinion on the merits and asked Günal Kurşun to be punished for “aiding an armed terrorist organization without being a member", meaning up to 15 years in prison.

At the 11th hearing on 19 February 2020, the defendants' arguments on the merits were heard. "We are respectable people, we all work to serve humanity without waiting for interest. In this case, our dignity was wanted to be destroyed," said Günal Kurşun. Recalling the torment and discrimination they experienced during their 13 days in custody, he said that the necessary investigations were not made during the proceedings. "The name of this case known to the public is Büyükada, but apart from the first hearing, it was not talked about the Büyükada meeting. In the last 10-15 years, it has turned into a case where all the work we have done is pretended, and human rights defenders and human rights are tried" he said. 

On 3 July 2020, the court sentenced Günal Kuşun one year and 13 months jail terms over “aiding a terrorist organization.”

The 3rd Criminal Chamber of the Istanbul Regional Court of Justice rejected the appeal of Günal Kurşun on 26 November 2020. 

The 3rd Penal Chamber of the Supreme Court of Appeals gave its decision on the appeals regarding the Büyükada case on October 17, 2022. Günal Kurşun's conviction was overturned due to "unlawful violation". The file was sent to the Istanbul 35th High Criminal Court, which is the first instance court, for a retrial.

At the first hearing on March 8, 2023, the court board announced its interim decision after announcing that it complied with the annulment decision. The delegation decided to continue the foreign travel ban on Kılıç and to investigate whether he used ByLock. As soon as the expert report on this issue came, it was decided to send the file to the opinion. 

The next hearing was held on 6 June 2023. The prosecutor of the hearing stated that there was no evidence against Günal Kurşun regarding the offense brought against the file after the Supreme Court's reversal, and demanded that Kurşun be acquitted because there was no clear and unequivocal evidence in the file that he had helped the Fethullahist structure. The court acquitted Günal Kurşun and the other three defendants on the grounds that it was not clear that they had committed the crime.