The Samoa Observer newspaper reported the political party whip of the ruling Human Rights Protection Party, Alai'asā Sepulona Moananu, saying caucus members will vote for a new deputy leader before then.
The vote comes after the role was left vacant last week by the sudden resignation of the long-serving MP Fiame Naomi Mata'afa from the ruling party.
A likely candidate for the role is the long serving MP for Palauli le Falefa constituency, Faumuina Tiatia Liuga.