Donald Trump is considering a major purge of his top White House staff as he searches for a "huge reboot" following the most damaging week of his presidential term, political sources in Washington said on Sunday night.

Taken aback by the fallout from his sudden dismissal of James Comey, the FBI director, and on the hunt for someone to blame, the president was said to be toying with firing senior allies, from Reince Priebus, his chief of staff, to Sean Spicer, his combative press secretary.

“He's frustrated, and angry at everyone,” one confidant told Mike Allen, the leading political journalist, adding that the president was thinking about "going big" with his response. "The question now is how big and how bold."