National contract talks between the United Auto Workers and General Motors Corp. continued Tuesday after a union executive told local leaders to prepare the troops for a strike. Negotiators were working against a midnight Friday deadline to reach a national contract covering about 300,000 active GM workers. UAW contracts with Ford Motor Co. and Chrysler Corp. also expire at the same time, but the union has chosen GM as its target for a strike. In all, more than 450,000 active auto workers are covered by UAW contracts with the Big Three automakers. The union's main bargaining goal is job security, and a union telephone recording said Tuesday that little progress had been made on that issue. ``The corporation must become more serious in their attitude,'' said UAW Vice President Stephen Yokich, in charge of the union's GM bargaining team. He told local union leaders they should be ready for a strike. ``I trust that you will do everything necessary to prepare the membership for a disciplined response to whatever action is required in the difficult days ahead,'' Yokich said. The last time the UAW struck GM over a national contract was in 1984, when the union staged a weeklong walkout at 12 assembly plants and the company's Technical Center in Warren, Mich. This year, members of UAW Local 659 at GM's AC Rochester West component plant in Flint staged a six-day strike that shut down seven assembly plants and parts of more than a dozen component factories. ``We haven't heard hardly anything,'' said UAW Local 662 Vice President Larry Howerton of Anderson, Ind. ``We're going to have to hear something pretty soon. We've got to be notified.'' There has been little news coming out of the talks this year. UAW and GM officials have been available to media only occasionally and when they have appeared, they rarely talked about contract details. They have preferred instead to say both sides were working hard and there still was time to reach an agreement before the deadline. So far, union officials have said tentative agreements have been reached on nearly all non-economic issues, such as military leave and jury duty provisions. But the economic issues, which include job security, are the tough ones. The UAW leadership has a strong strike authorization vote under its belt, clearing the way for it to call a strike against GM if an agreement cannot be reached.