Raila Odinga, who came second in Kenya’s presidential election, has filed a legal case challenging the result, his lawyers have said.
According to the electoral commission, Mr Odinga took 48.8% of the vote, losing to William Ruto’s 50.5%.
However, four of the seven electoral commissioners refused to endorse the outcome alleging that the way the final results were tallied was “opaque”.
The case will be heard by the Supreme Court.
Supporters of Mr Odinga gathered outside the court on Monday morning waiting for the lawyers to hand over the physical documents.
In 2017, the veteran politician successfully challenged the result of the presidential election, which he lost to Uhuru Kenyatta, and the Supreme Court ordered a re-run. The case highlighted logistical issues in the way the results were collated.
This time the Independent Electoral and Boundaries Commission (IEBC) tried to make the results process as transparent as possible by publishing the polling station tallies as soon as they were available.
An independent Kenyan monitoring group said the IEBC’s final result was in line with its own projection.