The Vice President of the Democratic Party in the Cook Islands, William Pera, says phone calls and rumours have been getting stronger in the past 24 hours, pushing for an urgent party conference after an MP was approached by the ruling Cook Islands Party.
Mr Pera says Wilkie Rasmussen, who is the Democrats' current leader but no longer holds a seat, is likely to be ousted.
The Prime Minister Henry Puna has said he wouldn't rule out a coalition between the two parties but Mr Rasmussen has called the idea wishful thinking.
Mr Pera says members of the Democratic Party executive are yet to meet and name a date for the conference.
"They need the conference so we will know who is going to lead us as a leader and which way we're going. Whether we're going coalition with the Cook Island Party, or with Teina Bishop and the other one."
The Democrats had earlier sided with the One Cook Islands Movement in the hope of winning power, should next month's by-election go their way.