Judges are set to decide next week whether Uhuru Kenyatta should be confirmed as Kenya's new president or new elections take place, a high-stakes test for a country still traumatised by political violence in 2007.
The East African nation's new Supreme Court, led by prominent rights defender Willy Mutunga, will determine whether or not to uphold allegations of widespread irregularities in the March 4 presidential polls.
"The pressure is immense," said political scientist and rights activist Lynne Muthoni Wanyeki.
Official election results show Kenyatta avoided a second-round run-off by the slimmest of margins, winning with just 50.07 percent -- although he was 800,000 votes ahead of his closest rival, outgoing Prime Minister Raila Odinga.
Odinga claims the poll was marred by irregularities including changes to the voter register, inflated numbers of registered voters and technical incompetence by the electoral commission.
He has urged supporters to stay calm while he challenges the outcome, and has promised to abide by the court's decision -- which is expected to come between Thursday and Saturday.
But tensions are understandably high: the elections in 2007 were marred by similar complaints of widespread fraud and descended into tribal bloodshed that killed more than 1,100 people and caused hundreds of thousands to flee their homes.
The violence tarnished Kenya's reputation as a bastion of stability in a region beset by civil wars and genocide.
Kenyatta, one of Africa's richest men, also faces trial for crimes against humanity at the International Criminal Court in The Hague in July for allegedly helping orchestrate the 2007/2008 violence.
"This is the acid test for the new judiciary," said Mwalimu Mati, who heads the Mars Group, a Kenyan anti-corruption and political rights watchdog.
He said the six judges in the Supreme Court, which was established under a constitution adopted in a 2010 referendum, are "perfectly aware they have to make a very tough decision."
Odinga says public faith in the state hangs in the balance: "The one institution in which all Kenyans still have faith is our new Judiciary," he said.
Kenyatta had also pledged to respect the decision, but his camp have attacked Mutunga, 65, for alleged bias -- quoting him as having in the past been openly supportive of Odinga's efforts to win the presidency.
"He can be very professional at times, but at times he has got very liberal views, and sometimes these liberal views override Mr. Mutunga as a professional," commented Moses Kuria, an analyst working for Kenyatta.
Mutunga has a reputation for independence, and served three years behind bars in the early 1980s under the authoritarian regime of Daniel Arap Moi.
But Wanyeki, a former head of Kenya's Human Rights Commission, said the top judge "was never a party person" but more a central pillar of the "organised constitutional reform movement."
This is seen as pitting him against 51-year-old Kenyatta, the son of Kenya's founding president whose family owns vast swathes of the country's richest lands and has a huge business empire.
Activist Mati said the top judge was sensitive to the criticism, and may therefore choose to leave a vote on how to proceed -- approve the result or order that new elections take place -- to the other five Supreme Court judges.
"It is possible that you could have a case where the chief justice would sit out (a decision). There is I think a bit of a whispering campaign against him anyway by all sorts of people," he said.