Directive 2001/20/EC, relating to the implementation of Good Clinical Practice (GCP) for clinical trials of medicinal products, required Member States to adopt the laws, regulations and provisions necessary to comply with the Directive. On 1st April, the United Kingdom adopted implementing Regulations under the European Communities Act 1972, subject to Parliament. This note describes implications of the UK's approach to implementing requirements of the Directive concerning the sponsor, particularly in relation to collaborative publicly funded trials. First, it describes what is possible under the Regulations. Then it goes on to discuss some considerations that might help partners in publicly funded trials to decide who may be expected to take on sponsorship responsibilities in different circumstances.