“That may be true,” said Alderman Sam Shropshire, the sponsor of the bill here. “But what they don’t tell you is that to make 100 billion plastic checkout bags per year, which is how many we use in the U.S. each year, it takes 12 million barrels of oil. No oil is used to produce recycled paper checkout bags.”

Jeffrie Zellmer, legislative director of the Maryland Retailers Association, said it took far less energy to recycle plastic than to recycle paper. Mr. Zellmer added that 90 percent of retailers used plastic bags and that costs could increase threefold or sixfold, eventually reaching consumers.

The commercial recycling coordinator for the City and County of San Francisco, Jack Macy, said that nationally 1 percent of all plastic checkout bags were recycled. “That means the rest end up in landfill,” Mr. Macy said. “And so the argument about plastic recycling being energy efficient isn’t a strong one.”

“Look,” Mr. Shropshire said, “in the end, the best option is for people to bring their own reusable bags. But if they fail to do that, then they can use paper bags that biodegrade faster than plastic and yet do not require any trees to be cut down.”

At the hearing, a lobbyist for Safeway called the bill un-American, saying it would take choices away from consumers.

For now, Mayor Ellen O. Moyer of Annapolis, a Democrat, remains undecided on the measure.

A spokesman for Ms. Moyer, Ray Weaver, said the city planned to distribute reusable bags to residents by the fall. To accomplish that, Mr. Weaver said, the city is considering teaming with sail makers to use excess material that teenagers in a jobs program may sew into sacks.

“I think it’s a smart move,” said Jim Martin, owner of the Free State Press, a small printing and copy store several blocks from the State Capitol, as he ordered business cards for a City Council member to be delivered in a plastic bag.