It’s the vast left-wing conspiracy.

President Obama’s senior adviser Valerie Jarrett leaked to the press details of Hillary Clinton’s use of a private email address during her time as secretary of state, sources tell me.

But she did so through people outside the ­administration, so the story couldn’t be traced to her or the White House.

In addition, at Jarrett’s behest, the State Department was ordered to launch a series of investigations into Hillary’s conduct at Foggy Bottom, including the use of her expense account, the disbursement of funds, her contact with foreign leaders and her possible collusion with the Clinton Foundation.

Six separate probes into Hillary’s performance have been ­going on at the State Department. I’m told that the email scandal was timed to come out just as Hillary was on the verge of formally announcing that she was running for president — and that there’s more to come.

Members of Bill Clinton’s camp say the former president suspects the White House is the source of the leak and is furious.

Obama and Valerie Jarrett will go to any lengths to prevent Hillary from becoming president. - Source

“My contacts and friends in newspapers and TV tell me that they’ve been contacted by the White House and offered all kinds of negative stories about us,” one of Bill’s friends quotes him as saying. “The Obamas are behind the email story, and they’re spreading rumors that I’ve been with women, that Hillary promoted people at the State Department who’d done favors for our foundation, that John Kerry had to clean up diplomatic messes Hillary left behind.”

Then, according to this source, Bill added: “The Obamas are out to get us any way they can.”

The sabotage is part of an ­ongoing feud between the two Democrat powerhouses.

Last fall, during the run-up to the 2014 midterm elections, Jarrett was heard to complain bitterly that the Clintons were turning congressmen, senators, governors and grassroots party members against Obama by portraying him as an unpopular president who was an albatross around the neck of the party.

Jarrett was said to be livid that most Democrats running for election refused to be seen campaigning with the president. She blamed the Clintons for marginalizing the president and for trying to wrest control of the Democratic Party away from Obama.

And she vowed payback.

My sources say Jarrett saw an opportunity to hit back hard when Monica Lewinsky suddenly resurfaced after years of living in obscurity. Jarrett discreetly put out word to some friendly members of the press that the White House would look with favor if they gave Monica some ink and airtime.

Relations have gotten even frostier in the past few months.

After the Democrats took a shellacking in the midterms, the White House scheduled a meeting with Hillary Clinton. When she showed up in the Oval Office, she was greeted by three people — the president, Jarrett and Michelle Obama.

With his wife and Jarrett looking on, Obama made it clear that he intended to stay neutral in the presidential primary process — a clear signal that he wouldn’t mind if someone challenged Hillary for the nomination.

“Obama and Valerie Jarrett will go to any lengths to prevent Hillary from becoming president,” a source close to the White House told me. “They believe that Hillary, like her husband, is left of center, not a true-blue liberal.”

If she gets into the White House, they believe she will compromise with the Republicans in Congress and undo Obama’s legacy.

“With Obama’s approval,” this source continued, “Valerie has been holding secret meetings with Martin O’Malley [the Democratic former governor of Maryland] and [Massachusetts Sen.] Elizabeth Warren. She’s promised O’Malley and Warren the full support of the White House if they will challenge Hillary for the presidential nomination.”

Edward Klein’s most recent book is “Blood Feud: The Clintons vs. the Obamas” (Regnery).