He is a dual citizen of the United Kingdom and Australia. He gave up his study at Bristol University, and while backpacking met Burmese refugees who engaged his interest in the plight of ethnic minorities in Burma. Mawdsley took up teaching English at a Burmese refugee camp, and became further involved when government forces burnt down the school.
He was arrested three times for his involvement and deported three times.
The second arrest was in 1998 for handing out stickers and playing songs for the pro-democracy movement. On arrest he was tortured for 15 hours, and sentenced to 5 years imprisonment, which was suspended after 98 days.
He was rearrested a third time in 1999 for illegal entry and sedition, and was sentenced to seventeen years in jail. His imprisonment was held to be arbitrary by the United Nations Working Group on Arbitrary Detention in 2000.
This time he spent 415 days in solitary confinement before his release in October 2000 after pressure was exerted by the United Kingdom Foreign Office on the authorities in Myanmar.
In February 2003 he co-authored New Ground with Benedict Rogers, a pamphlet advocating foreign policy based around freedom, dignity and the rule of law. This document has helped give rise to the Conservative Party Human Rights Commission, founded in 2005. He stood for the European Parliament Election, 2004.
In the United Kingdom 2005 general election, he unsuccessfully contested the Hyndburn constituency for the Conservative Party.
He wrote The Heart Must Break: the Fight for Democracy and Truth in Burma, published in the United States as The Iron Road: A Stand for Truth and Democracy in Burma. He is now a Catholic transitional Deacon with the FSSP, currently serving at Street Mary"s Church, Warrington, having studied to become a Priest at the FSSP seminary at Wigratzbad in Germany.