Paper or plastic? Seattle Mayor Greg Nickels and City Council President Richard Conlin say the answer is neither.

The two are proposing a 20-cent fee on disposable shopping bags at grocery, drug and convenience stores. Their plan announced Wednesday also calls for a ban on foam take-home containers, plates and cups at restaurants.

The proposal requires the City Council's approval.

Conlin and Nickels say paper and plastic bags and foam containers are bad for the environment, and they hope charging a fee will encourage people to bring reusable bags when they shop.

The 20-cent fee per bag would be divvied up — 5 cents for the retailer, 15 cents for the city. But retailers grossing less than $1 million a year will keep the entire 20-cent fee.

Seattle Public Utilities estimates that 360 million disposable bags are handed out in the city every year — most of them plastic.

Plastic bags are virtually indestructible, taking years to break down and commonly ending up in landfills.