John Snow, the US Treasury secretary, could become the first victim of an administration reshuffle following President George W. Bush's appointment of a new White House chief of staff.

Mr Bush fuelled that speculation yesterday by refusing to offer a clear endorsement of Mr Snow, whose two-year tenure at the Treasury has been marked by rumours of his imminent departure. "I'm glad you brought him up," he said in response to a question. "He has been a valuable member of my administration and I trust his judgment and appreciate his service."