The two leading candidates for New York City mayor will square off for their first debate, potentially giving underdog Joe Lhota his best chance to reverse the fortunes of his struggling campaign.

Lhota, the Republican nominee and former head of the region’s transit authority, is running out of time to cut into Democrat Bill de Blasio’s lead, which a series of recent polls shows is hovering near 50 points. The debate on Tuesday night, the first of three in as many weeks, comes exactly three weeks before the Nov. 5 general election.

Lhota likely would need a strong performance to bolster his sluggish fundraising enough to blanket the airwaves with ads in the campaign’s final weeks. He acknowledged that the moment was “crucial” for his campaign.

“This will be the first chance (when) Bill de Blasio will be standing next to me, Joe Lhota, talking about our visions for the future of the city of New York,” the Republican told reporters after marching in Monday’s Columbus Day parade.

“New Yorkers need to see that stark difference, our different philosophies,” he said. “Voters will get to see Bill and what he wants to do and Joe and what he wants to do.”

When asked what his debate strategy would be, Lhota simply replied: “to win.”

It may take a clear cut victory to reverse the feeling of inevitability that surrounds de Blasio, who is looking to become the first Democrat to be elected mayor since 1989. Many of the industries that normally back Republicans, like the real estate and financial sectors, have been wary of alienating de Blasio, who they see as the likely mayor, and have yet to give much in the way of financial support to Lhota.

Lhota has also been dogged by associations to the national Republicans, who polls suggest are being blamed for the federal government shutdown. And his top supporter, former mayor Rudolph Giuliani, is a polarizing figure in the city he used to govern and has not campaigned for Lhota since the primary.

De Blasio, meanwhile, has received endorsements from figures ranging from President Barack Obama to Gov. Andrew Cuomo. Hillary Rodham Clinton, whose 2000 Senate campaign was run by de Blasio, will be hosting a fundraiser for the public advocate this month.

Up big in the polls, de Blasio has run a classic front runner’s campaign, rarely appearing at public events where he could commit a gaffe. He defended his streamlined public schedule on Monday.

“I am very proud of what we’ve done throughout this campaign, having been out there in every neighborhood with every kind of New Yorker,” de Blasio told reporters at the parade. He and Lhota did not cross paths along the route.

The 60-minute debate will be broadcast live on network TV. Independent candidates were not invited by the event’s organizers.

Last week, the cable channel NY1 hosted a debate between Lhota and Adolfo Carrion, the Independence Party candidate. De Blasio declined to attend.

(AP)