Kenya's Supreme Court began hearing arguments Wednesday in challenges to the presidential election.
The court on Tuesday had a pre-trial where all parties confirmed their affidavits submissions.
Earlier on, the court had ordered a vote recount in 15 polling stations which are ongoing.
The court had also thrown out two other petitions on basis of lacking a mandate.
On Wednesday, lawyers representing the 1st petition, Raila Odinga took the floor to dislodge the election of William Ruto and the 5th President.
Odinga is among those challenging the results and alleging a range of problems with the election process.
Deputy President William Ruto was declared the winner earlier this month with just over 50% of the votes.
The court must rule on all challenges by the end of Monday.
The Supreme Court is the highest in the land, created under Kenya's 2010 constitution "as the final arbiter and interpreter of the constitution".
Its rulings are final and binding. If judges order an annulment, a new vote must be held within 60 days.
But if the court upholds the results, Ruto will become Kenya's fifth president since independence from Britain in 1963, taking the reins of a country battling inflation, high unemployment and a crippling drought.
The IEBC was under heavy pressure to deliver a clean vote after facing sharp criticism over its handling of the August 2017 election.
The court annulled that election in a first for Africa and ordered a re-run which was boycotted by Odinga. Dozens of people died during a police crackdown on protests.
Kenya's worst electoral violence occurred after the 2007 vote when more than 1,100 people died in politically motivated clashes involving rival tribes.
The court's announcement of the issues that it will examine is a common procedure in Kenya, known as a "pre-trial conference."