The Tongan Human Rights and Democracy Movement is to survey its membership before deciding who it will nominate for the by-election on Tongatapu created by the elevation of Fred Sevele to Cabinet.
Dr Sevele and Peauafi Haukinima, of the Niuas, this week became the first popularly elected MPs to be made Cabinet Ministers.
The promotion forced them to resign from their seats and by-elections are to be held next month.
Both are members of the Democracy Movement which has decided to nominate former MP, Aisea Taofi, in the Niuas, while the leading pro-democracy campaigner, MP Akilisi Pohiva, says it has five possible candidates for Dr Sevele's seat.
"All of them are members of the Human Rights and Democracy Movement and our office will carry out a survey on Tuesday that will decide who is going to represent the Movement in the by-election."
Akilisi Pohiva says with the exception of Lopeti Senituli, none of the candidates contested last week's poll.