Workers at the plant, the world's only producer of Volkswagen's New Beetle model, are calling for an 8.3 percent pay hike, above a company offer of 2.5 percent, said union spokesman Miguel Angel Galan.
The strike, an annual negotiating tool at the Volkswagen plant in the central Mexican state of Puebla, is due to start on Saturday at 11 a.m. local time (1600 GMT).
"We remain committed to working through this until very late to see if we can reach a favorable offer and avoid the strike," Galan said during a break in talks in Mexico City.
The Volkswagen plant 75 miles (120 km) east of the Mexican capital is the company's only plant in North America and exports mainly to the United States and Europe.
The plant has a target output of 400,000 vehicles this year compared to production of 347,020 in 2006, when the company suffered a six-day pay strike.
