Britain's top spy steps down after just 6 years as head of MI5 Sir Jonathan Evans ends 33-year career with the Secret Service Last year warned of the threat to the UK posed by Arab Spring Head of the MI5 Sir Jonathan Evans is to stand down next month, after 33 years with the Secret Service The head of MI5 is to quit next month, MPs were told today. Home Secretary Theresa May said Sir Jonathan Evans would step down after six years in charge of Britain's spies. It ends a 33-year career with the secret service, which has been transformed from dealing with the Northern Ireland troubles to the threats posed by the Arab Spring on cyber terrorists. Mrs May paid tribute his "dedicated" service over three decades. Speaking at Home Office Questions in the Commons, she told MPs: "During this time his contributions have varied from investigating counter espionage, developing and implementing key policies on security and most recently countering the threat of international terrorism. He has experienced the service evolving over the years and as Director General has lead the service through particularly challenging times of change and unrest, including the aftermath of the 7/7 bombings. His tireless work helped ensure the delivery of a safe and successful Olympic and Paralympic Games last year. Born in 1958, Sir Jonathan read Classical Studies at Bristol University before joining the Secret Service in 1980. He initially focused on Irish-related terrorism in the 1980s and 1990s, before moving on to international counter-terrorism investigations in 1999. He was appointed director of international counter-terrorism just 10 days before the attacks on the World Trade Centre and the Pentagon. He became Director General of MI5 in April 2007, succeeding Lady Manningham-Buller, and his departure comes at the end of his contract term. Home Secretary Theresa May told MPs that security threats to Britain had dramatically evolved since Sir Jonathan joined the service in 1980 Last year in a rare public speech just a month before the Olympic Games began in London, Sir Jonathan said the Arab world was in "radical transition." "Today parts of the Arab world have once more become a permissive environment for al Qaida," he said. Some will return to the UK and pose a threat here. This is a new and worrying development and could get worse as events unfold. So we will have to manage the short-term risks if there is to be a longer-term reward from the Arab Spring. Shadow Home Secretary Yvette Cooper said: "We also give thanks for the work Sir Jonathan Evans has done over many years for the security of this country."