Mesut Yilmaz, 73, has been in intensive care for a long time, being treated for lung cancer.
Ahmet Mesut Yılmaz was the leader of the Motherland Party (Turkish: Anavatan Partisi, ANAP) from 1991 to 2002, and served three times as Prime Minister of Turkey.
His first two prime-ministerial terms lasted just months (in 1991 and 1996), while the third ran from June 1997 to January 1999.
The first was brought to an end by defeat in the 1991 elections, the latter two by the breakdown of Yılmaz' coalition governments.