ALBANY, N.Y. – U.S. Sen. Charles Schumer said Sunday he's trying to get the federal government to prohibit airlines from charging a fee for carry-on baggage, calling it a "slap in the face to travelers.

The New York Democrat is making a personal plea to the Treasury Department to rule that carry-on bags are a necessity for travel, which would make them exempt from a separate fee outside the ticket price.

Airline passengers have always had the right to bring a carry-on bag without having to worry about getting nickeled and dimed by an airline company," Schumer said. "This latest fee is a slap in the face to travelers.

Schumer said carry-on bags often contain medications and other necessities, particularly for families. Carry-on fees artificially avoid higher ticket prices and the taxes applied to tickets, Schumer said.

The fee, however, is legal. The first airline to try it, Spirit Airlines, announced last week it would charge up to $45 for a carry-on, but that it was also reducing the cost of most tickets by $40.

Spirit CEO Ben Baldanza has said having fewer carry-on bags will help empty the plane faster, and the fee is intended to get customers to pay for individual things they want, while keeping the base fare low. Charging for checked bags but not carry-ons also means many passengers lug as much as they can onto planes.

There was no immediate comment Friday from the Treasury Department, which would handle the case because it's considered a tax issue.

Schumer wrote to Treasury Secretary Timothy Geithner seek to end what Schumer calls a loophole in law that allows the fees. Without action by Treasury, Schumer said he will introduce legislation.