Kenya's Supreme Court has begun hearing three petitions challenging last month's presidential election re-run, won by the incumbent Uhuru Kenyatta with 98% of the vote.
The court annulled the first presidential election in August, saying there were irregularities.
Mr Kenyatta won the re-run, after his main challenger, Raila Odinga, called on his supporters to boycott the vote.
Kenya's Attorney General Githu Muigai is fighting to make sure that the president's victory is not annulled a second time
Two of the legal cases ask the court to nullify Mr Kenyatta's victory on the grounds that the electoral body failed to call for fresh presidential nominations for the re-run.
The third is seeking to sanction opposition leaders for the civil unrest surrounding the elections.