Sen. Kamala Harris’ once-promising White House bid is rapidly unraveling — with her outgoing state operations director slamming the treatment of staff in a blistering resignation letter that claims “morale has never been lower,” a new report reveals.

Facing dwindling funds and tumbling polling numbers, the 55-year-old in recent weeks has laid-off swathes of staff in the run-up to the Iowa and New Hampshire primaries in a bid to revive her struggling 2020 bid.

But a New York Times investigation published Friday alleges the Harris campaign is internally imploding. Former and current campaign staff have broken ranks to claim Harris and her closest advisers lack focus and have failed to identify states and issues to campaign on.

In an excoriating resignation letter obtained by the Times, Harris’ outgoing state operations director Kelly Mehlenbacher accused the campaign of treating staff appallingly and having no plan to win.

“This is my third presidential campaign and I have never seen an organization treat its staff so poorly,” Mehlenbacher wrote in the Nov. 11 letter.

According to a Politico report published Wednesday, Mehlenbacher, a former staffer for Hillary’s Clinton campaign, has already accepted a role in rival Michael Bloomberg’s camp.

Mehlenbacher said it was the treatment of staff, particularly the laying off of dozens of aides at Harris’ Baltimore headquarters, which was the “final straw in this very difficult decision.”

“It is unacceptable that we would lay off anyone that we hired only weeks earlier. It is unacceptable that with less than 90 days until Iowa we still do not have a real plan to win,” she wrote.

With cash reserves running desperately low, Harris’ campaign manager and consultants have all taken pay cuts in the hopes of keeping the White House bid afloat.

An early powerhouse, Harris’ raised more than $12 million during the second quarter of the year.

But the Oakland-born lawmaker has failed to break any new ground — her polling numbers tumbling from 19 percent in July to just 8 percent in October, according to a CNN report.