Volkswagen ordered to bargain with UAW workers in Tennessee plant

US labour regulators have ordered Volkswagen to negotiate with maintenance workers at its plant in Chattanooga, Tennessee who voted to unionise, according to the United Automobile Workers.

The decision by the National Labour Relations Board marked a victory in latest round of the union's battle with the German automaker since some workers at the Volkswagen assembly plant voted to join, the UAW said late yesterday.

The December vote by maintenance workers was first time employees had chosen to organise at a foreign-owned auto-plant in the southeast US, where organised labour has long struggled to make inroads.

"This unanimous decision makes it clear that the company has been operating in violation of federal law by refusing to come to the bargaining table," UAW Secretary-Treasurer Gary Castle said in a statement.

Volkswagen did not respond to requests for comment. The company can appeal the decision in federal court.

The UAW lost a plant-wide vote to unionise in 2014 and Volkswagen had refused to recognise the maintenance workers, saying they did not represent the plant's production workers.

But in an August 26 decision, the NLRB found that Volkswagen Group of America's refusal was an "unlawful failure" to bargain with a certified union and ordered the company begin negotiations with the maintenance workers.

The NLRB order comes at a difficult time for the company, which is struggling to resolve criminal and civil allegations stemming from its emissions cheating scandal, in which Volkswagen has admitted to configuring millions of diesel vehicles around the word to defeat emissions testing.

US sales for Volkswagen fell 9.1 per cent in 29,384 in August, putting the first eight months of the year down 13 per cent over the same period in 2015, despite overall strong growth in the US automobile market.