Mayor Bloomberg today insisted the New York City Marathon should go on as scheduled, even as huge swaths of Gotham remain in ruins and with no electricity.

The famed five -borough race is set for Sunday, starting at the Verrazano-Narrows Bridge and ending in Central Park.

The mayor is banking on the restoration of electricity on several blocks of Manhattan, below 34th Street, thus relieving some police burden there.

“The marathon is not going to redirect any focus. Keep in mind by Sunday we’ll have electricity back downtown,” Bloomberg said.

“That will free up an enormous number of police. Also, a lot of the transportation needs that we have during the week aren’t there on the weekends.”

Former Comptroller Bill Thompson said he appreciates the importance the marathon — but believes there are too many other issues to address in New York right now.

“The New York City Marathon is one of our country’s quintessential events, but in the wake of the natural disaster that has struck our city and its residents we need to focus on more important priorities,” Thompson wrote on his Facebook page tonight.

“New Yorkers are suffering. Lives have been lost, homes destroyed, seniors stranded in public housing with no electricity and entire neighborhoods are suffering with scant access to fresh water, food and electricity. While I understand the importance of this event and the fact that it draws people from all over the world to watch and participate, I believe this year’s race needs to be postponed to a later date.”

Bloomberg has already forced postponement of the Nets’ debut at their new Barclays Center home, originally scheduled for tonight.

A huge selling point of Barclays is the transit hub at Atlantic Yards but most of those trains wouldn’t have been available to fans tonight.

While an NBA regular -season game is easy to reschedule, cancellation of this marathon — which draws competitors from across the globe — would have a much bigger impact.

“To us the marathon really epitomizes the spirit of New York City, the vitality, the tenacity, the determination of New Yorkers,” New York Road Runners President Mary Wittenberg said.

“Now our every effort is to once again tell the world that New York City, as the mayor would say, is open for business, and we welcome the support of the world at this trying time.”

With Post Wire Services and additional reporting by David K. Li