Tonga's Constitutional and Electoral Commission has recommended the monarchy be stripped of its powers to select and be part of the executive government.
The recommendations come in a final report on a proposed new system of government to be introduced for Tonga next year.
The report has recommended the King and Privy Council no longer be part of the Executive, which should only be answerable to the Legislative Assembly.
The King would no longer have the power to appoint the Prime Minister or Ministers at his pleasure.
It says he could only appoint the Prime Minister on advice of the Legislative Assembly and Ministers on the advice of the Prime Minister.
The Commission has recommended the number of people's representatives in Parliament be increased from 9 to 17, with nine nobles representatives.