DENVER - It's a debate that could shape the future of transportation in Colorado. The outcome will affect tens of thousands of people who use taxi and limo services on a regular basis.

Taxi companies are at odds with Uber, a smartphone app that allows customers to order a luxury car in minutes.

On Monday, the Public Utilities Commission recommended rule changes that would effectively put Uber out of business.

Both sides of this debate say their livelihoods, and customers' rights, are at stake.

Taxi driver Rita Pugh says far fewer customers are calling her cab, because of increased competition from Uber.

"We know it will put us out of business. I'm out of a job. I'm out of a house. I'm on the street with my children," Pugh said. "This is what's going to happen if Uber stays in and Uber is not regulated like every other taxi company."

Before the Uber app, customers had to call a limo company hours in advance. Now, they get a black car in minutes.

Kyle Brown with Metro Taxi says that's a big problem because Uber is not regulated like taxi companies.

"Luxury limos can act like taxis. We want Uber to act responsibly, play by the same rules," Brown said.

Uber CEO Travis Kalanick says his company offers a convenient way to connect licensed limo drivers with customers.

It operates in 15 major US cities, and is currently fighting legal battles in Denver and Chicago.

"It's not about whether we follow the rules, because we do. The taxi industry has lobbied against us. [The industry] tired to get the rules changed, tried to change laws," Kalanick said.

Emails released by Uber show Yellow Taxi has been lobbying the Public Utilities Commission to change the rules since last August, when Uber came to town.

The PUC is now proposing changes that would effectively make Uber's business model illegal.

"I would have to lay off some drivers," said limo company owner Kevin Labonte.

Labonte says, if Uber sticks around, he plans to expand.

"Right now I'm trying to hire five more drivers. I want to buy two more cars. But that's all on hold until we find out what happens with these rule changes," Labonte said.

Dozens gathered at a rally in Denver Monday evening to show support for Uber, as the company faces an uncertain future in Colorado.

The legal limbo continues until at least April 16, when a judge is expected to decide how a transportation brokerage like Uber can operate.

The Federal Trade Commission has weighed-in, saying the PUC's proposed rule changes could "significantly impair competition" and "harm consumers."

The city of Denver and PUC declined to comment Monday.

(KUSA-TV © 2013 Multimedia Holdings Corporation)