Chrysler and the United Auto Workers (UAW) union returned to negotiations Tuesday as the union threatened to go on strike if a new deal on wages and benefits is not reached. The UAW has said it will go on strike Wednesday morning if the two sides fail to agree on a new contract for 49,000 U.S. factory workers. The strike deadline, announced Monday, was the second time the UAW has threatened a national strike against a U.S. automaker in less than a month. The union caused a two-day work stoppage for General Motors Corporation (GM) last month before the two sides reached agreement on a new contract.