PHILADELPHIA (CBS) – Mayor Michael Nutter’s re-election campaign will go to court to challenge the candidacy of his one and only Democratic opponent: Milton Street.

The Nutter campaign will go before a judge arguing that Milton Street, brother of former mayor John Street, should not be on the May 17th primary ballot.

Spokesperson Sheila Simmons says they’re challenging whether Street meets the residency requirement.

“A candidate for mayor must be a city resident for at least three years, and we believe that not to be the case for Mr. Street,” Simmons said.

The challenge also questions the validity of some of the hundreds of nominating petition signatures that Street submitted.

Milton Street was sentenced in 2008 for failing to file tax returns and served about two thirds of his 30 month sentence.

Street says his residency can be confirmed by his parole officer.

Reported by Mike Dunn, KYW Newsradio