We are writing ahead of the College of Commissioners’ meeting tomorrow to urge you to ensure that the Commission’s legislative proposal on responsible sourcing of minerals includes a mandatory obligation for companies to undertake supply chain due diligence—that is, measures that companies must undertake to identify, prevent, mitigate, and account for human rights abuses in their supply chains...It is our view that the proposal must include a clear mandatory supply chain due diligence requirement for companies that place unprocessed or processed tin, tantalum, tungsten or gold, or manufactured products containing these minerals, on the European market...A European legislative framework that makes doing OECD-standard due diligence mandatory would bring EU companies up to the same responsible sourcing standard...[as the US]...Mandatory standards are needed because they are the only way of ensuring real, systematic change...Introducing a voluntary EU scheme would not only be redundant, it would also risk undermining the duty to protect human rights, which is well-established under international law...The Commission must take urgent action and ensure that the proposal is passed immediately and in its strongest form, based on a clear mandatory due diligence obligation.