President George Bush's press secretary has resigned and top adviser Karl Rove will abandon his policy co-ordination role to focus on political strategy in advance of November's congressional elections, writes Denis Staunton in Washington.
The moves come as Mr Bush's unpopularity reaches record levels and senior Republicans admit that they risk losing control of Congress in November.
The White House played down the significance of Mr Rove's move, but Democratic National Committee chairman Howard Dean said that Mr Bush's adviser was being punished for Mr Bush's declining popularity.
"After having his hand in nearly every bad Bush policy decision and nearly every scandal that has consumed the Bush White House, it is not surprising that Karl Rove was demoted this morning," Mr Dean said.
Press secretary Scott McClellan, who has had an increasingly difficult relationship with the White House press corps, announced his resignation during a brief appearance with the president yesterday morning. "The White House is going through a period of transition; change can be helpful, and this is a good time and good position to help bring about change. I am ready to move on," Mr McClellan said.
Mr Bush praised Mr McClellan's handling of the "challenging assignment" of handling the media, but made clear that he did not seek to persuade the press secretary to stay on.
"It's going to be hard to replace Scott. But, nevertheless, he's made the decision and I accept it," he said.
Yesterday's moves are the latest in a flurry of staff changes since Joshua Bolten replaced Andrew Card as Mr Bush's chief of staff last week.
The White House said that Joel Kaplan, a former colleague of Mr Bolten's at the Office of Management and Budget, will become deputy chief of staff for policy, leaving Mr Rove to focus on political strategy.
With Mr Bush's popularity at a record low, Republicans have been calling for months for a shake-up at the White House. Mr McClellan's credibility was damaged by his explicit denial that anyone in the White House was involved in leaking the identity of a CIA agent.
Vice-president Dick Cheney's former chief of staff Lewis "Scooter" Libby was charged with perjury after he admitted leaking Valerie Plame's identity as a CIA agent.
Mr Rove, who has advised Mr Bush since before the president became governor of Texas, has not been charged in connection with the leak inquiry, but he remains under investigation.