A Florida lawmaker is demanding that airlines not to act like a Scrooge during the busy holiday season.

Sen. Bill Nelson (D-Fla.), the ranking Democrat on the Senate's transportation committee, said Friday he had sent letters to major airline CEOs asking them not to hike fees for bags over the holidays, Bloomberg reports.

"These increased surcharges fly in the face of declining fuel costs and appear focused on increasing profitability on the backs of American families," Nelson wrote.

Two ultra-cost carriers, Spirit Airlines and Frontier Airlines, recently announced plans to raise bag fees during the upcoming holiday travel season. 

Spirit will increase bag fees $2 during the Christmas travel season, Dec. 16 through Jan. 4. Denver-based Frontier is raising bag fees $5 to $10 from Nov. 19 through Jan. 5.—and then again from Feb. 11 through April 4, about the time that most colleges let students out for spring break and during the summer travel season, from June 9 through Aug. 16.

Airlines have come under fire for their bag fees before, from both lawmakers and consumer groups.  Airlines collected $3.5 billion from baggage fees in 2014, according to statistics that have been compiled by the Department of Transportation

The two airlines defended the fees.  Spirit said other travel industry companies, like hotels and resorts, increase prices during high demand times --and that only charging those who check bags is a more fair and transparent approach than raising ticket prices.

"During times of peak travel, such as the summer months and holidays, there is much more demand for checked bags," Spirit Airlines spokesman Paul Berry said. "This demand brings added costs for baggage handling, manpower, airport infrastructure and added weight to aircraft, which burns more jet fuel."

Frontier Airlines President Barry Biffle said that the carrier changed its pricing structure earlier this year and that the fees are standard prices –while they offer a discount in other periods.

”I think the whole premise that Frontier has done something bad to consumers around the holiday is just unfair and completely deceptive and sensational, when the truth is anything but," he told Bay News 9. 

Meanwhile, the Canadian-based WestJet Airlines last week said it will eliminate free checked bags on all economy fare flights to Europe and sun destinations starting early in the new year.  The carrier will impose a $25 baggage fee to new economy bookings for flights as of Jan. 6.