Former President Abdullah Gül will not attend a referendum rally President Recep Tayyip Erdoğan and Prime Minister Binali Yıldırım will jointly hold in his hometown of Kayseri on Sunday.
Turkey will hold a referendum on April 16 on a constitutional reform package that will introduce an executive presidency.
Sources close to Gül told media outlets that Gül does not want to attend political rallies.
Gül is known to be a supporter of the parliamentary system of governance which Turkey currently has.