The closely watched immigration talks between the U.S. Chamber of Commerce and the AFL-CIO are hitting the skids because of a disagreement over temporary worker visas.

The business lobby and the labor federation are clashing over how many temporary visas should be allowed in a new program for immigrant workers, and the gulf between the two sides appears to be wide.

Randy Johnson, the Chamber’s senior vice president for labor, immigration and employee benefits, said Friday that the trade association has pushed to cap the program at 400,000 temporary worker visas. Union officials are pushing for a much lower figure, he said, in the low tens of thousands.