SACRAMENTO, Calif. — In a bid for more support, legislators made late amendments Friday to a proposal that would make California the first state to ban single-use plastic grocery, convenience and drugstore bags.

The proposal by Assemblyman Julia Brownley, a Democrat, was amended to address concerns that the bill would cost jobs and burden consumers with a nickel charge for paper bags. The bill would ban single-use plastic carryout bags from supermarkets and large drugstores starting in 2012, and smaller grocers, convenience and liquor stores in 2013.

Assembly Bill 1998 has faced furious lobbying from the plastics industry as legislators approach a Tuesday deadline for passing bills. The bill passed the Assembly, but faces a tough vote in the Senate.

Under Brownley’s amendments, the bill now earmarks $2 million from an existing recycling promotion fund so factories in California can obtain loans and grants to retool manufacturing lines to produce heavy, reusable plastic bags.

Two factories that would be eligible for aid are in the districts of Assembly Speaker John A. Perez and Sen. Gil Cedillo, both Democrats. Roplast Industries of Oroville, which makes reusable grocery bags, announced Friday it supports the bill.

Brownley’s bill also would have allowed stores to charge a nickel if consumers wanted a recycled paper bag. But another amendment now allows retailers to only charge what they pay to buy the bags.

If customers prove they rely on food stamps or subsidies for women and infants, moreover, they would get bags for free.

Another amendment retains plastic-bag recycling at stores.

In a statement Friday, Brownley said her bill takes steps to protect jobs in California, and enjoys a “”historic mix”” of support among unions, grocers and retailers.