 In 1986, he resigned from the Secretary-General of the National Security Council, to be Secretary-General to the Prime Minister of Prem Tinsulanonda.His image of the will of the intelligence expert resulting in the nickname of "CIA of Thailand" and got another nickname, "Co-Prime Minister" from Prem's secretary-general.Prasong has been a long-time critic of Thaksin Shinawatra since Thaksin's entry into politics in 1994.