President John Mahama accused Ghana's main opposition leader of deliberately undermining confidence in the voting process before Wednesday's election by failing to issue a clear call for peace whatever the outcome.
The West African country prides itself on its record as a stable democracy with peaceful transitions of power, unusual in Africa, and civic leaders often call for a violence-free vote.
But after a long court battle to settle the outcome of the 2012 vote, tensions have resurged ahead of this week's election, with analysts giving opposition leader Nana Akufo-Addo a good chance of defeating Mahama's bid for a second and final term.
"The opposition is creating a situation in the minds of their supporters not to accept the results of the elections (if they lose)," Mahama said in an interview late on Monday after opening an airport project in Ghana's second city Kumasi.
"The leader of the opposition ... has never climbed on a platform and called his people to order. (Akufo-Addo has) never, ever said, 'I am a man of peace. I am calling on all of you. I don't want violence,'" he told Reuters.
The opposition New Patriotic Party (NPP) dismissed Mahama's accusation but said problems with last week's early voting when some people could not find their names on the electoral register suggested the election might not be fair.
"What we are calling for is free and fair elections ... Peace and everything depends on the fairness of the election," NPP spokesman Nana Akomea said.
Mahama said he was only "cautiously optimistic" about winning a final term. "If I lose...I will hand over and leave."
Ghana was one of Africa's fastest growing economies until it hit a buffer in 2014 due to spiking inflation, an unexpectedly high budget deficit and a plunge in global prices for its gold, cocoa and oil exports.
Mahama says the government has improved people's lives and built fresh infrastructure despite the fiscal crisis, which it says it has largely resolved with the help of continuing IMF aid. The opposition says the government has mismanaged the economy and squandered revenue from Ghana's natural resources.
Mahama narrowly beat Akufo-Addo in 2012 and the opposition challenged the result, which led to an eight-month court tussle.
The NPP won in 2000 and 2004 before losing in 2008. Given the expected closeness of Wednesday's vote, many NPP supporters note that since 2000 no party has won three consecutive terms in office. If the pattern continues the NPP would likely win.
Mahama's supporters note that no sitting president has lost a re-election bid since 1992. His predecessor died in office.