Istanbul mayor Ekrem Imamoglu’s lawyer Mehmet Pehlivan on Tuesday said he had filed a lawsuit to restore his client’s degree, which had been revoked in March.

The degree had been revoked by Istanbul University, the university from which Imamoglou graduated, following the submission of a report by Turkey’s higher education council (Yok) which found that the university in northern Cyprus at which he began his studies before transferring to Istanbul was not adequately recognised.

“The university degree that [Imamoglu] received lawfully 31 years ago was revoked on March 18 … in clear violation of the principles of the rule of law and through an abuse of administrative authority,” Pehlivan began.

He also stressed the significance of the date on which the case was filed, May 6, the sixth anniversary of the date in 2019 on which Turkey’s supreme electoral council had voted to annul the results of that year’s Istanbul mayoral election after the ruling AK Party had alleged voter fraud in the wake of Imamoglu’s narrow victory over their candidate and former prime minister Binali Yildirim.

A rerun election was then held in June of that year, with Imamoglu then beating Yildirim by a landslide.

“May 6 is the symbolic day of those who fought for the ideals of democracy, law, and complete independence in Turkish history … For this very reason, we found it meaningful and important to file our lawsuit on May 6,” Pehlivan said.

He added that the case “does not only aim to protect [Imamoglu’s] personal rights”, but that it is also “a fight we are undertaking to protect the rule of law, the principle of legal certainty, and fundamental rights and freedoms”.

Imamoglu was one of 28 people to have his degree revoked at the time. In the immediate aftermath, he described the university’s decision as “unlawful”, adding that its board of directors “does not have the authority to make such a decision”.

“The authority lies solely with the board of directors of the faculty of business administration. The days when those who made this decision will be held accountable before history and justice are near,” he said.

He was arrested the following day, accused of having “led a criminal organisation”, while the Istanbul chief public prosecutor’s office said it had obtained “footage of money counting inside the CHP”.

Additionally, charges of “aiding the Kurdish Workers Party (PKK)”, a proscribed terrorist organisation in Turkey and the European Union, were also filed against Imamoglu, with the Istanbul chief public prosecutor’s office saying that “individuals with connections to the PKK were hired in the Greater Istanbul municipality and its subsidiaries”.

The Istanbul chief public prosecutor’s office said these charges are related to activities during last year’s local elections, where Imamoglu won re-election as Istanbul mayor.

His arrest sparked protests across Turkey, with Turkish nationals living in Cyprus also taking to the streets.