These posts are presently filled after the appointment by the King in conjunction with the Privy Council.
The Akilisi Pohiva-led government wants to control all the key appointments because it claims these officials sometimes work against the government.
But publisher Kalafi Moala, who campaigned for democracy alongside Mr Pohiva for many years, says there is a need to maintain the separation of powers to avoid a possible conflict of interest.
"In terms of having the one executive have so much power that they appoint all of these key positions and the authority can be so much concentrated in the hands - it can be a partisan type of appointment; they can choose their own people to be in those key positions. So that is the reason for the existence of the King's authority to be able to appoint those positions."
Photo: AFP Tongan publisher and veteran journalist, Kalafi Moala