The late politician’s son, Bhichit Rattakul, said his father had passed away at Siriraj Hospital, two weeks after he was admitted to receive treatment.
Before taking his last breath, Bhichai managed to convey his wishes to every member of his family, Bhichit said.
The Democrat Party also posted a message of condolence on its website for the passing of its fourth leader.
Bhichai, a veteran politician, who was an MP several times, also held many key government positions, including deputy PM, Parliament president, House speaker and foreign minister.
Born on September 16, 1926, to Bhisal and Wilai Rattakul, Bhichai had nine siblings. He completed his secondary education at Bangkok Christian College before furthering his studies at Hong Kong’s Saint Stephen’s College.
He began his political career by joining the Democrat Party in 1958 under the leadership of Khuang Aphaiwong and was elected as Bangkok MP in 1969.
In 1975, Bhichai became foreign minister under the government of MR Seni Pramoj and in 1982 became the fourth leader of the Democrat Party. He led the party until 1991.
The late politician then became deputy PM from 1983 until 1990 and again from 1997 to 2000 in Chuan Leekpai’s second term.
Royally-sponsored bathing rites will be held at 5.30pm in Wat Thepsirin’s Kawee Niramitr Pavilion on Tuesday.