In 2002 Prime Minister Thaksin Shinawatra invited Wissanu to become a minister in his cabinet, changing from the civil service to a political career, but also threatened to dismiss him as secretary-general in case of refusal. Wissanu agreed and Thaksin made him deputy prime minister, responsible for legal and parliamentary affairs. At that time, Thaksin had seven deputy prime ministers. Wissanu's successor as secretary-general of the cabinet was his personal friend Borwornsak Uwanno. During the 2005–06 Thai political crisis and after the dissolution of parliament, both Wissanu and Borwornsak resigned their government posts.
