Donald Trump has named his budget director, Mick Mulvaney, as acting chief of staff after what became a tortuous search to fill what was once one of Washington’s most coveted jobs.

Now hiring for 'the worst job in government': Trump's chief of staff Read more

The US president tweeted on Friday that Mulvaney “has done an outstanding job” in his administration and would take over from John Kelly in the new year.

Trump deemed the 51-year-old his “acting chief of staff” but it was not immediately clear what that meant for the length of his tenure as the president’s gatekeeper.

According to a pooled report, a senior administration official told reporters: “There’s no time limit. He’s the acting chief of staff, which means he’s the chief of staff. He got picked because the president liked him, they get along.”

The official cited Mulvaney’s experience as a “former member of Congress” and described him as “fiscally responsible”, the report added.

Trump praised Kelly’s service and called him a “great patriot” in the tweet.

Sign up for the new US morning briefing

But the unusual arrangement met with instant scepticism. Chris Whipple, the author of The Gatekeepers: How the White House Chiefs of Staff Define Every Presidency, said: “I do think an ‘acting’ chief of staff is almost a contradiction because the coin of the realm for chiefs of staff is speaking for the president, having the authority to execute his agenda, and you can’t do that if you have an expiration date.

“Erskine Bowles, who was Bill Clinton’s chief of staff, told me the moment anyone suspects you don’t speak for the president, people sense it, they smell it, and you’re nothing but an overblown scheduler.”

Whipple added: “You can’t be an empowered chief of staff when you’re a temporary appointment. Donald Trump desperately needs an empowered chief of staff who can tell him what he doesn’t want to hear and enforce his agenda. This doesn’t sound like the solution to his problem.”

Trump announced last week that Kelly, who served in the post for more than a year, would soon be departing. His first choice was Nick Ayers, the vice-president’s chief of staff, who bowed out after being unable to come to an agreement on how long he would serve in the post.

Earlier on Friday Chris Christie, the former governor of New Jersey, also ruled himself out of contention, announcing that he told Trump that “now is not the right time for me or my family to undertake this serious assignment”.

US investigates whether Trump's inaugural cash was spent improperly – report Read more

Trump’s first chief of staff, Reince Priebus, lasted only six months amid White House chaos. Kelly, a retired Marine Corps general, was brought in to impose discipline but relations with the president quickly broke down and he never saw eye to eye with Trump’s daughter Ivanka, and son-in-law Jared Kushner.

Priebus and Kelly were photographed together at a White House Christmas party this week. “Having a great time at the Whitehouse Christmas Party!” Priebus wrote on Twitter.

Trump tweeted late Friday that there were “many people” who wanted the position and that “Mick M will do a GREAT job!”

The White House said Russell Vought will be Mulvaney’s replacement as the director of the Office of Management and Budget. Mulvaney tweeted on Friday night: “This is a tremendous honor. I look forward to working with the President and the entire team. It’s going to be a great 2019!”

Sarah Sanders, the White House press secretary, said that Mulvaney would not be resigning from the Office Of Management and Budget, “but will spend all of his time devoted to his role as the acting chief of staff for the president. Russ Vought will handle day to day operations and run OMB.”