U.S. auto maker Tesla Inc should respect fundamental labour rights, including that of collective bargaining by labour unions, Norway's $1.5 trillion sovereign wealth fund, the world's biggest stock market investor, told Reuters on Friday.

The electric vehicle producer faces a backlash in the Nordic region from unions and some pension funds over its refusal to accept a demand from Swedish mechanics for collective bargaining rights covering wages and other conditions.

Norges Bank Investment Management, which operates the Norwegian fund, is Tesla’s 7th biggest shareholder with a 0.88% stake worth some $6.8 billion according to LSEG data.

“We expect companies in which we invest to respect fundamental human rights, including labour rights,” NBIM said in a statement to Reuters when asked about Tesla’s conflict with its Swedish workers.

“In 2022 we supported a shareholder proposal at Tesla that asked the company to introduce a policy to respect the right to organise,” it added.

The 2022 proposal, which NBIM said was supported by 32% of those who voted, called on Tesla to adopt a policy of respecting labour rights such as freedom of association and collective bargaining. The company’s board recommended a ‘no’ vote.