Former Nairobi Governor Evans Kidero has urged the High Court to allow him join a petition challenging his successor Mike Sonko.
Through his lawyer Tom Ojienda, Dr Kidero said he has evidence that will assist the court arrive a fair decision.
He said he participated in the election as an ODM candidate and lost to Sonko, and therefore has a stake in the petition.
Governor Sonko, however, dismissed his application questioning why he is joining the case late.
Mr Sonko, through his lawyers Harrison Kinyanjui and Cecil Miller, told Justice Msagha Mbogholi that Kidero is seeking to join the case to introduce new evidence, a move that would prejudice him.
Sonko's election was challenged by two voters - Japheth Muroko and Zachaeus Okoth.
Dr Kidero has claimed that more than 60 per cent of the Forms 37A, used to declare Sonko the winner, contained irregularities.
He said some of the forms had multiple anomalies, others had no polling station tallies and others lacked requisite security features. The anomalies affecting over 308,918 votes, Dr Kidero has argue.
Dr Kidero said among the 798 of the 1,300 Forms 37A used, some were not signed by the agents and presiding officers, others had varied dates yet they were announced from the same polling station, while others were not stamped.
In reply, Mr Sonko questioned Dr Kidero' sources of electoral data. He said the quoted figures were not contained in the forms.
Mr Sonko also dismissed claims that agents from other parties were barred, and asked the court to dismiss this claim because Dr Kidero did not name the affected polling stations.
Sonko further argued that the application by Kidero to join the case is an afterthought.
The IEBC also questioned why Dr Kidero did not file a petition to challenge Mr Sonko's win within the 28 mandatory days given by the law.
The Independent Electoral and Boundaries Commission said Dr Kidero only sought to join the case as an interested party 52 days later.
Justice Mbogholi will give his ruling on November 16.