Europe’s largest trade union is trying to gain control of the works council at Elon Musk’s Tesla gigafactory near Berlin, in an industrial relations showdown marked by lawsuits and mutual accusations of slander.

The works council, an elected body of employees that negotiates everything from working hours to pay deals with a company’s management, is considered an entrenched aspect of the German corporate world, particularly in the car industry.

But it was a bone of contention at the Tesla plant in Grünheide, about 20 miles (30km) south-east of Berlin, even before the gates opened almost four years ago.

There have been regular clashes at the plant – which employs about 10,000 workers and is the US electric carmaker’s only production site in Europe – between the turbo-capitalist approach of Tesla’s management and Germany’s tradition of a social market economy, which relies on worker representation and collective bargaining.

Voting in elections to the works council, which is now controlled by non-trade union members, began on Monday and will close on Wednesday.

The face-off has been portrayed as a battle of wills between the century-old IG Metall union and Musk, who alleges it is threatening economic growth. The union has framed the fight as nothing less than an existential threat to European workers’ rights and accuses Musk, the world’s richest man, of wanting to “bust the union”.

IG Metall says Tesla provides inadequate working conditions and lays off employees it has accused of shirking. It argues that a collective agreement to protect workers is needed.

Tesla, in turn, says the union is interested only in expanding IG Metall’s membership. It rejects the idea that working conditions are poor and says it pays above average wages.

Musk has said the outcome of the dispute could determine the future of the plant and whether investment plans go ahead.

The row escalated last month when Tesla’s management accused an IG Metall member of illegally recording a works council meeting. The union denies the accusation. Both sides took legal action against each other over the claims.

The government of the state of Brandenburg has been called upon to mediate but the regional economics ministry has urged the parties to reach a deal on their own. It said it would encourage Tesla to embrace a collective agreement.

IG Metall has nominated 116 candidates for the works council in an effort to secure a simple majority of 19 out of 37 seats. It won 16 seats in the last vote two years ago when the council consisted of 39 seats.

The dispute, in which Tesla’s management has been portrayed as unusually confrontational by labour experts, has created yet more negative headlines for the car manufacturer, which is struggling with its sales in Europe partly through tough competition from cheaper Chinese EV models.

In Germany, there has been a consumer backlash against Musk in response to the support he has given to the far-right Alternative für Deutschland party.