James specialises in extradition, human rights and public law. In extradition he is regularly instructed to act for both requested persons and Governments in complex cases, having appeared in courts at all levels, including the Supreme Court. James has significant expertise in Part 2 requests, having appeared for the Turkish, Albanian and Norwegian Governments and represented individuals sought by countries including the Russian Federation, Falkland Islands, United States, Turkey and the Ukraine. James also has particular expertise in arguments regarding the validity of requests and he has acted in the majority of the lead cases on prison conditions in Part 1 territories, including Portugal, Lithuania, Romania, Hungary and Greece.

In public law, James is frequently instructed to act in leading public law cases with national security and/or criminal features. He has appeared for the Government as junior before the Supreme Court, High Court and SIAC. James has acted in TPIM (Terrorism Prevention and Investigation Measures Act 2011) proceedings and was instructed as junior in the first ever Temporary Exclusion Order (under the Counter-Terrorism and Security Act 2015) imposed on a returnee from ISIL-controlled territory. He acts in judicial reviews against immigration decisions, damage claims and inquests.