Rival NFL stadium backers shared the stage for the first time Thursday at the Millennium Biltmore Hotel in Los Angeles.

Sitting on opposite sides of a four-person panel, John Semcken, of the proposed L.A. Stadium, and Ted Tanner, of AEG’s proposed Farmers Field, touted their competing plans in front of nearly 200 audience members.

Both are competing to lure an NFL team back to Los Angeles.

Semcken’s case for billionaire Ed Roski’s proposed hillside stadium in the City of Industry centered on an already fully developed plan that will not require any public funds. Tanner focused on the expansion and revitalization of the Los Angeles Convention Center, which is packaged with Farmers Field.

The event came one night after the L.A. Planning Department held its first “scoping meeting.” That meeting kicked off a series of events welcoming the public to weigh in on the Farmers Field project.

But Thursday brought Semcken and Tanner together for the first time.

The pair disagreed on a number of issues, but tempers never flared.

Semcken, as he has done in the past, continued with bold predictions that Tanner was unwilling to match.

At one point, a member of the public asked Tanner: “Are we going to be stuck with Farmers Field (as the name)?”

Semcken quickly quipped, “No, it’ll never be built.”

Moderator Frank Stoltze, of KPCC, neutralized the comment with a quick jab back at Semcken: “Don’t make me question you about naming rights,” he said.

Earlier this year, AEG announced a $700-million naming rights deal with Farmers Insurance. Semcken, on the other hand, has hinted at a billion-dollar naming rights deal for his stadium, but no such deal has been reached.

Semcken would not comment on any further developments on Thursday.

Nor would either party comment on which teams they’ve spoken to, despite constant probing by Stoltze.

What they would comment on was how each of their plans would provide an economic boom to the region.

Semcken argued L.A. Stadium would be the ideal location, centered in Los Angeles, the Inland Empire and Orange counties. The city of L.A. would be a big benefactor, he said.

“The Super Bowl in New York is actually in New Jersey,” he said. “But all the parties are going to be in New York. So the net impact is fantastic. There’s no money that New York is putting in the stadium and they’re getting the benefits.”

AEG’s proposed stadium, however, has stolen away much of the momentum after the naming rights deal and support from much of the L.A. City Council.

Also on the panel Thursday was councilwoman Jan Perry, a 2013 mayoral candidate who was recently named chairwoman of a special committee to examine the $1.4 billion Farmers Field project.

Perry praised the project, which she called “an opportunity.”

She also addressed concerns raised the previous night. A number of downtown residents questioned whether the stadium would drive up rent, and thus, drive them out.

“Here is an opportunity to build on what is already a burgeoning community,” Perry said. “They (AEG) have never shown an unwillingness to engage in that discussion.”

Also of concern has been whether taxpayers will have to foot some of the bill for Farmers Field. AEG has pledged that no public money will be needed. However, the company has called for the city to issue $350 million in municipal bonds to upgrade the Convention Center.

Those bonds would be paid back over the course of around 25 years through ticket taxes, property taxes and private AEG funds.

Semcken disagreed with the use of bonds to pay for “other buildings.”

“At Staples Center, we had a ticket tax, but we wanted to use parking taxes and property taxes and business taxes and we couldn’t,” he said. “Every single tax generated by Staples Center goes to taxable authorities in the city of L.A. It’s 100 percent upside. We’re not collecting it to build other buildings. And in the City of Industry, we’re doing the same thing.”

The duo also disagreed on transportation.

“Our hope and our expectation is that we will see unprecedented use of public transit — using rail lines and using buslines,” Tanner said of the downtown project.

Perry discussed the potential of utilizing the Metro’s blue line.

“I think what the developers can help us do is create a very strong visually obvious linkage between the blue line and the campus (Farmers Field, L.A. Live, Staples Center), so that people will feel far more enthusiastic about taking the blue line from other points in the region,” she said.

Semcken, who has been outspoken about the lack of parking availability in the Farmers Field proposal, argued that NFL fans want to enjoy tailgating at a park.

Public transit is one of the last things on their mind, he said.

On how the night went, Semcken replied, “You can see just how the questions are asked, they’re asked from a West Los Angeles perspective and the region is much bigger than that. When you think about where the fans are coming from, where the businesses are that are going to provide the sponsorships, and where the residents are that are going to be affected, it’s a much bigger region than just here in downtown.”

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