PORTLAND – Maine would adopt vehicle emissions standards based on California rules under a proposal before the state Board of Environmental Protection.

California passed the nation’s strictest standards for car emissions in 1990 and amended them in 1998 to include pickup trucks and sport utility vehicles. The amendment also included provisions to encourage the sales of electric cars.

On Dec. 21, the BEP will consider adopting similar rules for the vehicle model years 2004 to 2010. The original California rules, which cover the 2001, 2002 and 2004 model years, are already in effect in Maine.

The Department of Environmental Protection opposes including California’s mandate for zero-emission vehicles, according to Ron Severance of the Bureau of Air Quality Control.

The mandate, adopted in 1990, requires clean or nearly clean vehicles to make up 10 percent of the fleets automakers sell, beginning in 2003. At least 4 percent would have to be zero-emission vehicles, which currently means battery-operated electric vehicles. Manufacturers could reduce that number by offering them for sale before 2003 or making cars that get more than 100 miles between battery charges.

Severance said zero-emission vehicles are too expensive for the average consumer. Other disadvantages, including the need to recharge batteries, make them impractical, he said.

The Maine Automobile Dealers Association supports the DEP’s position.

Tom Brown, a spokesman for the association, said most dealers can order zero-emission vehicles for customers who want them.

The Natural Resources Council of Maine wants the zero-emission vehicles requirement included in Maine’s rules.

“The council is surprised by, disappointed with, and totally opposed to the recommendation to abandon Maine’s requirement for sales of the cleanest vehicles available,” said Sue Jones, the council’s clean air project director. DEP inspectors will visit Maine dealers to check if 2001 model cars comply with the rule. Severance said that because Massachusetts adopted California’s rules in 1995, most cars in New England meet California’s standards.

Vermont is the other New England state that has adopted California’s rules.