– President Donald Trump’s top pick to be his next chief of staff, Nick Ayers, will not take the job and instead will leave the White House at the end of the year, reopening negotiations over who will succeed the departing John Kelly.

Four other candidates are now believed to be in the running to direct Trump’s White House, administration officials said Sunday. Ayers, a longtime operative who is now Vice President Mike Pence’s chief of staff, said in a tweet that after departing he “will work with the MAGA team to advance the cause.”

“Thank you realDonaldTrump, VP, and my great colleagues for the honor to serve our Nation at The White House,” he said.

Trump’s new list of potential chiefs includes Office of Management and Budget Director Mick Mulvaney, who is also acting director of the Consumer Financial Protection Bureau, and Rep. Mark Meadows, R-N.C., a leader of the House Freedom Caucus, according to a White House official.

Sources said Ayers would work with the super PAC that was set up to assist the president’s re-election campaign.

Trump had previously spoken with Ayers about the top administration job and had settled on him as Kelly’s likely replacement, the president’s advisers said.

But Ayers, who has young children, had insisted on serving temporarily, frustrating Trump, who had wanted a replacement to stay on through 2020.

Ayers was also skeptical of taking the job based on the challenges that Kelly and his predecessor, Reince Priebus, faced in the position, and talks between the two sides broke down, according to an administration official with direct knowledge of the negotiations.

The 36-year-old Ayers also had faced opposition among many senior White House aides, who worried that his elevation could trigger departures of other high-level staffers.