asked the Secretary of State for Social Services whether the Committee on Safety of Medicines requires clinical trials supporting a request for a product licence to be double blind trials.

This is not a standard requirement. The design of a clinical trial will depend on the condition being treated and the effectiveness of the medicinal product being tested. In some cases a double blind trial is essential, but in others, for example where a very effective drug is to be used to treat a life-threatening condition, such a trial would not be appropriate.