John Walters, head of the Bush administration's non-partisan drug agency, and his deputies engaged in a campaign blitz on behalf of vulnerable Republican members of Congress ahead of last year's mid-term elections, according to documents released yesterday.

Karl Rove, the chief political strategist for President George W. Bush, singled out the efforts of officials at the Office of National Drug Control Policy (ONDCP), which shapes US drug policy, at a White House meeting after the congressional election last November.