This report by Giles Wilkes, former special adviser to Vince Cable, analyses the policymaking role of a departmental special adviser. It is based upon the author’s experience in the Department for Business, Innovation and Skills and focuses on how special advisers  drive through policy by reconciling many different interests. The report provides examples of how special advisers can ease the way for good policy and block the way for bad. And it provides examples of how the very opposite can happen.