After graduating from university, Jonathan worked as an Environmental Health Officer for five years before joining Tesco in 1998. He spent his first two years at Tesco in an audit role, reviewing factory production standards across chilled, produce and MFPE categories across Europe. In 2000 he moved into an Operational Standards role, working with stores to improve store standards and from there to a wider policy role covering health and safety for the business. During this time he also took on international standards governance roles, travelling across the Tesco Group.
In 2007 Jonathan shifted focus to specialize on environmental compliance issues and began to take on an advisory role for the business across a range of sustainability issues including seafood and packaging. Jonathan joined the Tesco Responsible Sourcing team in 2014 to head up work on marine sustainability and commodities linked to tropical forest deforestation including palm, soy, wood and paper and beef.