The carmaker plans to have more than 7m electrified vehicles on the road by the end of this decade, with two thirds of them fully electric. That means greater sourcing of critical raw materials, such as those used in the batteries that drive them. Those batteries include lithium, cobalt and nickel. As well as the environmental impact of mining these materials, there are human rights issues associated with some of the areas in which they are mined.

According to BMW, since 2014 all of its direct suppliers have been contractually obliged to respect human rights, comply with expanded environmental and social standards, and to introduce management systems to promote occupational safety and protect the environment. The carmaker said these requirements must be passed on to subcontractors. Mercedes-Benz recently announced similar measures to ensure its battery supply chains are sustainable.