The Turkish government has signed a contract to expand Marmara Prison, the largest prison in Europe, which accommodates several high-profile figures due to overcrowding.

A new two-storey facility, covering an area of 832 square meters, will be constructed within the Marmara Prison complex, formerly known as Silivri.

Located in Istanbul's Silivri district, the prison holds several dismissed mayors from the Republican People's Party (CHP), including Ekrem Imamoglu, as well as Gezi Park protest detainees Can Atalay and Osman Kavala, among others whom the Turkish opposition describes as political prisoners.

The company awarded the construction contract is expected to complete the project by May 8, although the purpose of the new building remains unclear.

Marmara Prison is widely recognized as a detention center for journalists and political dissidents, with an official capacity of 11,000 inmates.

According to a 2019 report by the Turkish Parliament's Human Rights Inquiry Committee, the prison was housing 22,781 inmates at the time, with persistent reports of overcrowding and inmates forced to sleep on the floor.

Established in 2008, the prison complex spans more than 1 million square meters and comprises nine closed prisons as well as an open prison facility covering 437,000 square meters.