He has worked as outreach director for the charitable organisation and advocacy group CAGE, (formerly 'Cageprisoners') to represent those detainees still held at Guantanamo, as well as to help those who have been released to get services and integrate into society. He has travelled on speaking tours, and worked to persuade governments to accept former detainees for resettlement. In 2010, Cynthia Stroum, then-U.S. Ambassador to Luxembourg, commented "Mr Begg is doing our work for us...", adding that Begg's "articulate, reasoned presentation makes for a convincing argument".