London, UK Politicians, from left, the former prime ministers Sir John Major, David Cameron and Theresa May; the Speaker of the House of Commons, Sir Lindsay Hoyle; the home secretary Priti Patel, and the prime minister, Boris Johnson, attend the requiem mass for Sir David Amess MP at Westminster Cathedral. The Southend West MP was killed during a constituency surgery in Leigh-on-Sea in Essex. Ali Harbi Ali has been charged with his murder and also with preparing acts of terrorism