Philadelphia's annual professional bike race, a signature event that unites the city from the Benjamin Franklin Parkway to the Manayunk "Wall" each June, is on the verge of cancellation, a potential victim of the global economic downturn and the city's own budget woes.

Organizers of the race, the TD Bank Philadelphia Cycling Championship, say they face a $500,000 budget gap, about half of which is the result of the Nutter administration's decision to charge for city costs.

At the moment, organizers have raised about $1.2 million of the $1.7 million needed to have the race.

The situation is similar to the one faced by the Mummers Parade late last year. The parade was saved by a last-minute fund-raising campaign.

Race organizers say that they have leads on new sponsors, but that the effort is running out of time. They have given themselves until Monday to find funding or they will cancel the event, set for June 7. This year would mark the 25th running of the race.

"It is not the city's fault," said Jerry Casale, a co-founder of the race. "The city has been a great partner for 24 years. Everybody is facing an economic crisis."

The race draws hundreds of thousands of fans each year.

As a cycling competition, it is the premier single-day professional bike race in the United States. Among its past winners are seven-time Tour de France champion Lance Armstrong and former Olympic speed-skating gold medalist Eric Heiden.

As a public festival, it has few peers on Philadelphia's calendar, creating a daylong block party running from Center City to Manayunk and Roxborough.

It also stands out for taking an obscure residential incline and turning it into an internationally known cycling icon, the Manayunk Wall.

"This is an event that adds so much to the quality of life and vibrancy [of] the city," said Loree Jones, former city managing director, who now is executive director of the Manayunk Development Corp. "It would be a terrible loss."

Terry Bateman lives on the Manayunk Wall, has been a race volunteer, and now serves as volunteer coordinator.

"It would be so sad," Bateman said, contemplating the end of the race. "The excitement would be gone. People here would be very disappointed. I know this is the city's race, but for people here, it is our race, Manayunk's race."

That sentiment was recognized by City Councilman Curtis Jones, who represents the Fourth District, which includes Manayunk and Roxborough.

"The bike race is a staple of the Fourth District," Jones said. "We understand there is a recession, but we don't want to lose this. I'm going to try to rally some people with deep, deep pockets and see what we can do."

According to race organizers, it is an event that more than pays for itself, bringing between $15 million to $20 million in revenue to the city, between fans and competitors.

The genesis of the race's troubles is twofold.

It has lost a number of sponsors over the last year, in part because of the economy. Two of those sponsors alone - CSC and Rock Racing - were worth $225,000.

Then there are the city's own financial problems, which have left the Nutter administration grappling with ways to fill a $2 billion budget shortfall over five years.

As it looks for ways to balance its budget, the city has asked more of such public events.

For the last several years, the city had not asked race organizers to cover any of the city's attendant costs, according to Dave Chauner, a co-founder of the race and president of Pro Cycling Tour, which runs the event.

This year, in light of the city's financial crisis, the Nutter administration notified the race organizers they would be expected to cover costs including clean-up and police. Chauner said the figure has settled at about $250,000.

In recent weeks, the organizers have worked to cut their costs. They canceled races in Allentown and Reading that were to precede the Philadelphia race.

And they have been scrambling to find new revenue, by way of sponsors and fans willing to buy tickets for finish-line seating.

Chauner said he and Casale had about 20 potential new sponsors but, because of the economy, it was difficult to get commitments quickly enough for a race that is rapidly approaching.

"This is such a great event, it would be terrible to lose it," Chauner said. "Jerry and I are not going to give up. We are not going down without a fight."

Contact staff writer Christopher K. Hepp at 215-854-2208 or chepp@phillynews.com.