NEW YORK, July 22 — The United States on Thursday filed its fifth labour complaint in Mexico to determine whether worker rights were violated under a regional trade pact, requesting a review into a US-owned auto-parts plant in northern Mexico.

The request to probe the factory, owned by Michigan-based VU Manufacturing, came after activists alleged the company interfered in workers' ability to choose their union, the Department of Labour said.

"The US Department of Labour seeks to level the playing field for workers and businesses on both sides of the border," US Labour Secretary Marty Walsh said in a statement.

Previous US complaints under the 2020 United States-Mexico-Canada Agreement (USMCA) have also focused on Mexico's auto sector, calling for probes into US automaker General Motors, Japan's Panasonic, Italian-French carmaker Stellantis and US company Cardone.

VU Manufacturing, in the border city of Piedras Negras in Coahuila state, produces interior car parts such as arm-rests and door upholstery for various auto brands. The company, whose Mexico plant operates as Manufacturas VU, did not immediately reply to a request for comment.

The US request to Mexico flagged its concern that workers since at least June 2022 were blocked from supporting a new union, La Liga Sindical Obrera Mexicana.

Mexican authorities have 10 days to determine whether to accept the US request. The economy and labour ministries did not immediately reply to requests for comment.

A key goal of the USMCA is to improve workplace conditions in Mexico, and sanctions can include revoking tariff-free status for plants that violate the rights to freedom of association and collective bargaining. — Reuters