TUSCALOOSA, Ala. (AP) — Workers at two Mercedes-Benz plants near Tuscaloosa, Alabama, were voting against joining the United Auto Workers union Friday, in a test of the UAW’s ambitious plan to unionize auto plants in the historically nonunion South.

Unofficial totals posted on a union website Friday afternoon showed that 1,096 workers, or 55% of the total votes counted, were against the union. The UAW reported 899 votes in favor.

It was not yet clear how many of the 5,200 eligible workers had cast a vote in the five-day election run by the National Labor Relations Board.

The voting at the two Mercedes factories — one an assembly plant, the other a battery-making facility — comes a month after the UAW scored a breakthrough victory at Volkswagen’s assembly factory in Chattanooga, Tennessee. In that election, VW workers voted overwhelmingly to join the UAW, drawn by the prospect of substantially higher wages and other benefits.