The National Committee for Political Change in Tonga has supported a combination of three models for democratic reform at the weekend.
The committee met on Saturday to discuss what proposals they would submit to government.
It has given the government until the first week of December to respond to the proposals.
MP Clive Edwards says there will need to be a few amendments to various acts and the constitution.
He says he has prepared some of the extensions and amendments to the relevant acts.
A 34-member parliament would be elected by a common roll, including six nobles' seats.
The Prime minister would then select his cabinet after being chosen by members.
The house would also include representatives from Tongans in New Zealand, Australia and the United States.
Other changes would allow dual citizenship.