Amber Rudd will throw down the gauntlet to technology bosses on Thursday after the Westminster attack sparked a furore over companies’ responsibilities to support counter-terrorism investigations and remove extremist content.
The Home Secretary will raise the issue of encryption and security services’ access to terrorists’ communications at a summit with senior executives from a number of firms including Google, Microsoft, Twitter and Facebook.
Although she will voice her concerns about encryption, the main focus of the meeting will be on efforts to tackle terrorist material and propaganda online.
Technology giants have repeatedly faced calls to do more to detect and take down terror-related content from their platforms.
It comes on the day a coroner is due to open the inquest of 52-year-old Khalid Masood, who was shot dead by police after killing four people and injuring dozens of others during a rampage through the heart of London lasting less than two minutes.
On Wednesday the acting head of Scotland Yard, Craig Mackey, said the Westminster attack should be a “wake-up call” for firms.
Ms Rudd will use the private meeting to urge companies to do more to ensure terrorists and extremists are not able to use their platforms to disseminate propaganda.
It is understood ministers want communication service providers to use technical solutions so extremist content can be automatically identified before it is widely circulated.
The Government is also pushing for firms to form an industry-wide body.
A fresh debate over authorities’ access to communications was sparked after it was reported that Masood’s phone connected with encrypted messaging service WhatsApp shortly before the atrocity.
Controversy has centred on so-called end-to-end encryption, which means messages are encoded so only the sending and receiving devices can read them.
At the weekend Ms Rudd said there should be “no place for terrorists to hide”.
She stressed that end-to-end encryption “has a place” but there should be a mechanism for police and security services to access communications relating to terrorism after obtaining a warrant.
Privacy campaigners and opposition politicians cautioned against any move to build “back doors” into encryption, saying this could weaken cyber security for law-abiding citizens.
WhatsApp has said it is “co-operating with law enforcement as they continue their investigations”.
The topic of encryption will be discussed further in future meetings.
An inquest for the four victims was opened and adjourned at Westminster Coroner’s Court on Wednesday.
Kurt Cochran, 54, Leslie Rhodes, 75, and Aysha Frade died after Muslim convert Masood drove at pedestrians on Westminster Bridge.
Pc Keith Palmer, 48, died from a single stab wound to the chest before Masood was killed.