Embattled Toronto Mayor Rob Ford has withdrawn from the mayoral race, and a city clerk says Ford's brother will run in his place.

The mayor's nephew, Mike Ford, who was running for a council seat in the mayor's old ward, has also withdrawn, and city officials say Rob Ford will now seek a seat on the City Council.

Doug Ford, the mayor’s brother and a city councilor who had been the mayor's campaign manager, submitted his registration papers to run for mayor in his brother's place Friday afternoon.

"My heart is heavy when I tell you that I'm unable to continue my campaign for re-election as your mayor," Ford said in a statement. "I have asked Doug to run to become the next Mayor of Toronto, because we need him. We cannot go backwards."

The shuffle occurred just hours before a city deadline to determine who will appear on the election ballot.

Ford has been receiving treatment for a tumor in his abdomen. Biopsy results won't be back for a week and a definitive diagnosis is pending.

Earlier Friday, the Toronto Sun reported that the mayor could be facing "a surgery and chemotherapy and could be on his back for six to eight weeks," the CBC reported.

"As many of you know I've been dealing with a serious medical issue, the details of which are unknown. But I know that with the love and support of my family, I will get through this," Ford's statement said.

Ford became an international celebrity last year after acknowledging using crack cocaine in a "drunken stupor" following months of denials. He returned to work in June after a rehab stint for drugs and alcohol.  He had forged ahead with his campaign despite persistent calls for him to quit amid several scandals.

Doug Ford told the Sun Friday he would follow whatever the mayor decided for his future.

He also told the newspaper his brother "is in for the fight of his life."

The deadline to add a name to the ballot was Friday afternoon, giving the Fords a short time to complete necessary paperwork. Two other major candidates are still in the running for mayor. The election is scheduled for Oct. 27.

The Associated Press contributed to this report.