MONROVIA, Liberia — Liberia’s Supreme Court will rule Monday on a petition asking to delay the runoff presidential election after a complaint said the National Election Commission failed to investigate claims of irregularities in the first round of the vote to replace Africa’s first elected female president.

All activity to prepare for Tuesday’s runoff has been halted until the court’s decision. A delay of the vote is almost certain, as the electoral commission has said it would be hard to meet deadlines now.

The court heard arguments Friday. Charles Brumskine, the Liberty Party candidate who placed third, has asked the court to grant an Oct. 27 petition to halt the runoff vote until the claims of irregularities are investigated. He argued before the packed court that the Oct. 10 first round was marked by fraud.

His party petitioned the court to compel the election commission to investigate the complaints.

A lawyer for the commission, Alexander Zoe, asked the court to dismiss the petition and allow the runoff vote to proceed.

Brumskine told The Associated Press he looks forward to a rerun of the October vote, in which 20 candidates vied to replace Nobel Peace Prize winner Ellen Johnson Sirleaf.

“The process was completely corrupted,” he said. “We now realize elections were lost long before election day.”

International soccer star George Weah placed first in the October vote, followed by Vice President Joseph Boakai. They were to face off Tuesday after neither won the required 50 percent plus one vote to win outright.