Updated 6pm
Members of the PN general council began voting on Wednesday on whether the party members should be invited to confirm Adrian Delia as party leader or hold a leadership election.
The decision to let the 1,630 councillors decide the way forward was taken at a stormy meeting of the party's executive last Thursday.
It came after Delia lost confidence votes within the parliamentary group and the executive itself earlier this month.
Former party leader and prime minister Lawrence Gonzi was among the first to cast his ballot on Wednesday.
Voting continues on Friday afternoon and all day on Saturday at PN headquarters in Pieta' and the sub-headquarters in Sannat, Gozo.
Results are expected to be announced around 8pm on Saturday.
After the parliamentary group’s no confidence vote earlier in July, a group of MPs nominated Therese Comodini Cachia as opposition leader if Delia was removed, even taking their decision to the president.
President George Vella, however, said he would not remove Delia as Opposition leader.
Among those to be named as possible future PN leaders are Comodini Cachia, MEP Roberta Metsola, Bernard Grech, Mark Anthony Sammut, Joe Giglio and Alex Perici Calascione.
Adrian Delia was made leader of the PN three years ago, the first leader to be elected directly by the party membership. He has refused to step down despite dismal opinion polls and controversy over Whatapp chats he had with suspected Daphne Caruana Galizia murder mastermind Yorgen Fenech, insisting he did nothing wrong.
Both those in favour and against Delia have been campaigning intensively over the past few days.
A decision by the councillors to ask the members to confirm Delia would be seen as a victory for the embattled leader, who has, however, said he would seek re-election if the decision is to hold a new leadership election.
A confirmatory vote could take place in the second half of August but a leadership contest would stretch into September, with more than one round of voting if there are more than two candidates.