Papua New Guinea's Electoral Commissioner has been urged not to declare the election result in the prime minister's seat before other electorates.
Peter O'Neill's seat of Ialibu-Pangia in Southern Highlands province is one of the first electorates to finish polling, according to the Electoral Commission.
A number of leading political opponents of Mr O'Neill are concerned that officials are counting in his seat even as most other electorates across PNG have not completed polling.
The National Party leader Kerenge Kua, National Alliance leader Patrick Pruaitch, Pangu Pati's Sam Basil, Ben Micah of the People's Progress Party and former prime minister Sir Mekere Morauta have released a statement.
In it they urged the commissioner, Patilias Gamato, not to undermine the integrity of the election by declaring the Ialibu-Pangia election result first.
"Doing so would send a clear signal to Papua New Guineans that the manipulation of the election is continuing with one aim in mind - the formation of a People's National Congress-led Government," the statement said.
O'Neill's seat was the first declared in the 2012 election, which was seen as giving him a distinct advantage in the ensuing lobbying to form a coalition government.
The prime minister's opponents said there must not be a repeat in 2017.
"Ialibu-Pangia at the very least should not be declared before counting ends in other Southern Highlands seats."
As the end of the scheduled two weeks of polling approaches, the election so far has been dominated by widespread flaws in the electoral roll, irregularities with ballot papers and ballot boxes.
Sir Mekere has been very critical of the conduct of the election, saying poor planning by the Electoral Commission has amounted to "abuses of people's constitutional rights and freedoms".
He and other candidates in the national capital earlier alleged that Mr Gamato was hand-picked by the prime minister to deliver a manipulated election.
Mr O'Neill has said Sir Mekere has no evidence to back this up, and accused the former prime minister of presiding over a failed election in 2002.
"The 2002 poll was an absolute failed election marred by violence and corruption, and in the end seven seats could not be declared before the recall of Parliament," said Mr O'Neill.
However the flood of complaints about omissions from the electoral roll in this election has fuelled public concern that this election is destined to be a failed one.
"Mr Gamato, the Election Steering Committee head Mr Isaac Lupari, and the Prime Minister have done enough damage already," said the candidates in their statement.
"To declare Ialibu-Pangia first would be the final nail in the coffin of public confidence and would render the election result meaningless.
"To try to give an advantage to one party by selective declarations of seats would be just one more piece of unacceptable manipulation."