This open letter to Mark Zuckerberg is from the Home Secretary, alongside US Attorney General Barr, Secretary of Homeland Security (Acting) McAleenan, and Australian Minister for Home Affairs Dutton.

The letter requests that Facebook does not proceed with its plan to implement end-to-end encryption across its messaging services without ensuring that there is no reduction to user safety and without including a means for law enforcement to obtain lawful access to the content of communications.

The written testimony submitted to the US Senate Judiciary Committee hearing: ‘Encryption and Lawful Access: Evaluating Benefits and Risks to Public Safety and Privacy’ from the Director of National Security, lays out the UK government’s position and concerns.