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 50.49%.
However, four of the seven electoral commissioners refused to endorse the outcome alleging that the way the final results were tallied was “opaque”.
The seven judges at the Supreme Court will have 14 days to make a ruling.
One of the arguments that Mr Odinga’s Azimio coalition is putting forward is that there were just over 140,000 votes that were cast but were not included in the final tally, according to an extract from the legal documents seen by the BBC.
This number could be enough to prevent Mr Ruto from reaching the 50%-plus-one-vote threshold needed to avoid a second-round run-off.
Supporters of Mr Odinga gathered outside the court in a suburb of the capital, Nairobi, on Monday morning waiting for the lawyers to hand over the physical documents. Their placards read: “Protect our Vote” and “Electoral Justice Now!”
They cheered and chanted as the presidential candidate and his running mate, Martha Karua, arrived at the court to formally submit the case.
Speaking last week, Mr Odinga described the result as a “travesty”, adding that the election should be declared “null and void”.
This is the third time in a row that he has gone to court to get an outcome overturned.
In 2017, the veteran politician successfully challenged the result of that year’s 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.
A week ago, there were chaotic scenes at the national tallying centre moments before the final result of the 9 August poll was about to be read out.
Some of Mr Odinga’s political allies stormed the stage and scuffles broke out. Two electoral commissioners were injured and four others left the compound to hold a press conference to denounce the outcome.
Nevertheless, IEBC chairman Wafula Chebukati proceeded with the announcement and handed Mr Ruto the certificate confirming that he was the winner.
Last week, Mr Ruto said he would respect the court process, which is part of the country’s electoral law.
“I’m a democrat. I believe in the rule of law. I respect our institutions,” he told journalists.