Jonathan has been active on child labour issues since 1989, when he worked with street-living and working children in Puebla, Mexico. He has worked for Anti-Slavery International since 1992, coordinating its child labour programme from 1995 to 2006. During this time Jonathan has collaborated closely with local NGOs in Asia, Africa and Central/Latin America and the Caribbean.

He has specialised particularly on the situation of child domestic workers: developing and undertaking research; developing policy; lobbying governments and international institutions; authoring, contributing to and editing a number of publications for Anti-Slavery International and others, including: Child Domestic Workers: A handbook for research and action (1997); Child Domestic Workers: Finding a Voice - A handbook on advocacy (2002); Child Domestic Workers: A handbook on good practice in programme interventions (2005); Child Domestic Workers, UNICEF (Innocenti Digest no.5, 1999); good practice reports for ILO-IPEC and articles in academic journals including the International Journal of Children’s Rights and Childhood. He has advised ILO-IPEC, UNICEF and Save the Children UK on the issue. Jonathan has a first degree in Sociology (1992) and a Masters degree in International, European and Comparative Law (1994).