Transportation Secretary Samuel Skinner is labeling as unrealistic and irresponsible Senate legislation that would require tougher auto fuel economy standards, saying it would cause hundreds of additional traffic deaths. Skinner denounced the legislation Friday only hours after the Senate voted 68-28 to consider the proposal next week. The measure would require automakers to increase average fuel economy of new cars to 35 miles per gallon by 1995 and to 40 miles per gallon by 2001. Supporters contend the higher fuel economy requirements, once fully implemented, would save 2.8 million barrels of oil a day, but key opponents promised to continue fighting the measure. Skinner told a news conference that if the measure clears Congress, he would strongly advise President Bush to veto it. But the measure likely will run into serious opposition in the House, where supporters must maneuver around the Energy and Commerce Committee, whose chairman, Rep. John Dingell, D-Mich., is strongly opposed to the legislation. Skinner said the bill is ``unrealistic, irresponsible and, more important, unattainable.'' He said auto executives have convinced him there is no technology to achieve the bill's goals without making cars smaller. ``It should be called the highway fatality bill,'' Skinner said. He cited a new study by the National Highway Traffic Safety Administration that concluded there is a clear link between reducing the size of cars and increasing numbers of traffic deaths. Joan Claybrook, NHTSA administrator during the Carter administration and now president of the consumer group Public Citizen, disputed claims that cars necessarily will have to be made smaller to burn less fuel. She cited a Transportation Department research vehicle built in the 1970s that achieved 43 mpg while providing occupants improved protection over conventional cars. Sen. Donald Riegle, D-Mich., who has led the opposition to the plan, said he would continue the fight against bringing the measure to a vote next week. ``We've just had the first inning of this nine-inning game,'' said Riegle. ``We hope and intend to win this fight.'' But the Senate vote reflected the growing support in Congress for an effort to reduce U.S. reliance on foreign oil, a subject in the spotlight since Iraq's invasion and annexation of Kuwait early last month. In floor debate, Riegle said the bill's fuel savings wouldn't likely begin phasing in until 1995 and a better response to today's oil crisis might be to return to a national speed limit of 55 mph. Later, a Riegle spokeswoman said the senator didn't necessarily support a change in the speed limit and would vote against such a measure if it were introduced. Sen. Richard Bryan, D-Nev., the bill's sponsor, described the measure as a message to the automakers ``that they're going to have to look at fuel economy and not just muscle cars.''