Michael has been Oxfam's Senior Policy Adviser on humanitarian and security issues since October 2005, working primarily on research, policy development and lobby, and coordinating a team of nine policy advisers and researchers. The team works on issues such as the protection of civilians in conflict, arms control, and improvements in the quantity and quality of humanitarian aid.

For the previous six years, he held a similar role as Senior Policy Adviser in the trade and investment team, working on a range of economic issues, including the impact of patent rules on access to medicines.

Prior to that, Michael was Oxfam GB's Country Representative for Brazil, based in the North-eastern city of Recife.

In the 1980s, Michael worked as a Latin America programme officer in Christian Aid, focused mainly on Central America. His first job overseas was in Peru and Ecuador where he spent five years as a volunteer programme co-ordinator.