As Prince Harry and Meghan Markle’s longest-serving staffer prepares to leave — their entire brand is under threat, multiple sources tell Page Six.

“They’ve essentially shuttered Archewell,” a source tells us as news broke Monday that James Holt is stepping down as chief of their charity, Archewell.

“After five incredible years in Los Angeles, it’s time for my family to return to London,” the businessman told People in a statement.

“When I pass the baton to the team leading Archewell Philanthropies in the coming months, I’ll do so with immense pride and optimism for what lies ahead,” Holt added.

“I’ll miss my colleagues deeply, and I’m grateful to Harry and Meghan for everything they’ve done — for me, and for the countless people we’ve worked to support.”

Harry, 41, and Markle, 44, also applauded Holt’s “stellar support” after about ten years of service, telling the outlet, “His enthusiasm and talent in overseeing our philanthropic endeavours have been extraordinary.”

A rep for the Duke and Duchess of Sussex added that Holt “will remain a senior philanthropic advisor for the couple and Archewell Philanthropies, supporting their humanitarian trips overseas in 2026.”

Now, Page Six can reveal that Holt’s long-time counterpart, Archewell VP Shauna Nep, is not even a full-time employee, but is working on a “consultant” basis.

In addition to this, there are just a few employees left on Harry and Markle’s production business — and they could lose more staffers if Markle’s show, “With Love, Meghan,” is not brought back for another season.

“Anyone still there is simply an enabler, enamored with what the couple once was, not who they are today,” claimed one industry source familiar with the Sussexes. “From a year ago, they have decreased their staff by at least 80-85 percent.”

As Page Six previously revealed, the Archewell Foundation, which recently rebranded as Archewell Philanthropies, was down to just Holt and Nep.

The Sussexes spent the past few months in cost-cutting talks for their charity and even discussed selling the foundation.

Holt’s departure follows that of former Archewell senior staffers, Genevieve Roth, Christine Schirmer and Ashley Hansen.

“Every time someone leaves Harry and Meghan say they are staying on in some capacity,” said another source, “But they are never heard from again.

“Shauna hasn’t been a full-time employee in some time,” added the source, “This is crazy — they have lost their Foundation in a matter of weeks.”

On the production side, the Sussexes still have Chanel Pysnik as head of unscripted, alongside producer Tracy Ryerson.

However, the source added, “If Meghan’s Netflix show isn’t picked up for another season then what happens to their staff?”

A rep for Harry and Markle did not immediately return Page Six’s request for comment.

Last week, the duo also lost their publicist, Meredith Maines, after less than a year of employment.

An insider told Page Six that Maines “did what she needed to do” for the couple by helping launch Meghan’s podcast and TV show.

Over the summer, Harry and Markle also lost their Los Angeles deputy press secretary, Kyle Boulia, and their UK press officer, Charlie Gips.

At the time, two additional employees also left the team.