Calls are growing for President Trump to “clean house” at 1600 Pennsylvania Avenue, after a series of leaks aimed at embarrassing and undermining the president sprung from the White House this week.

A White House source estimates more than 60 percent of employees at the National Security Council are not Trump administration appointees, but career officials who were appointed to the White House from other agencies under the Obama administration.

The source said there are “whole departments” at the NSC with only one Trump appointee.

“I think the lesson here is that these things are going to continue to happen until the Trump White House does a serious housecleaning,” said Fred Fleitz, a former CIA and Bush administration official.

“Now under civil service rules, it’s difficult to fire them and I’m not sure they should be fired, but they can be reassigned. And people who are going to promote the president’s policies rather than undermine them — he needs to put those people in place,” he added.

The White House did not respond immediately to a request for comment on whether it would reassign or appoint new NSC officials anytime soon.

Earlier this week, “current and former” officials leaked to the Washington Post that Trump had discussed “highly classified” information with Russian officials last week.

A day later, an “associate” of former FBI Director James Comey told the New York Times that Comey allegedly wrote a memo saying Trump asked him to end his investigation of former National Security Adviser Michael Flynn.

Then a “current and a former official” — presumably the same ones who talked to the Post — revealed to the New York Times that Israel was the source of the information Trump spoke with Russian officials about.

Fleitz believes it is those career officials assigned to the NSC under Obama who leaked Trump’s conversation with Russian officials to former Obama officials and media outlets.

“I understand there was something called a memcon, a memo of conversation, that was written on it, and I suspect that that document may have reached people in these various agencies who had been put in place, promoted by the Obama administration, they’re Obama loyalists, and they’re just aching for information that they can use to undermine this president,” he said.

“At the NSC, there’s no confirmation process, people can be let go immediately, and new people can be brought in,” he added.

But a major problem for the Trump administration is that there is no budget to bring in new people at the NSC until September, when the new fiscal year starts, the White House source said.

But compounding the problem is that there are also hundreds of political positions currently unfilled at departments that interface with the NSC, such as State and Defense.

So far, out of 57 Senate-confirmed political appointee positions at the Pentagon, only two have been filled — Defense Secretary Jim Mattis and Air Force Secretary Heather Wilson.

Fleitz recommended the Trump administration move much faster on getting those slots filled — both those that require Senate confirmation and those that do not.

“Concerning positions that require confirmation, you can put in people on an interim basis,” he said. “Congress has no say over it. I don’t doubt Congress will try to slow roll trying to put in confirmed people, but they can’t be blocked.”

“The process has to start for many, many of these positions, hundreds of them, confirmed positions. There haven’t even been nominations,” he said. “Their names have to be put forward, in front of the Senate, let the Democrats play their games, we’ll have them in place in a couple of months, maybe a few months,” he said.

He also recommended immediately filling positions that don’t require Senate confirmation.

“But below that level we can start staffing these positions right now. Right now that process has to start. I say the Deputy Assistant Secretary level, Deputy Under Secretary, these are unconfirmed positions,” he said.

“Office directors in places like the State Department and the Defense Department, you know, this is something that this administration needs to start moving on,” he said.

In some cases, Obama political appointees have also “burrowed in” to the civil service, which serves from administration to administration. There are even some Obama political appointees who have been appointed positions in the Trump administration.

Calls have also been growing for the Trump administration to identify and prosecute the source of the leaks, including from at least one Democrat.

“We need to ask questions about why is this intelligence community trying to upend the President of the United States with these leaks?” former House member Dennis Kucinich said on Fox News Tuesday.

“Look, I disagree with President Trump on a number of issues, but on this one, there can only be one President and somebody in the intelligence community is trying to upend this President in order to pursue a policy direction that puts us in conflict with Russia. The question is why? and who? And we need to find out,” he said.

Sen. James Risch (R-R.I.), a member of the Senate intelligence committee, said the leaker should be brought to justice.

“The real story here is, there’s a weasel here. And that is the person who reported about this conversation. This is a person who is a traitor. They betrayed their own country. They betrayed their families and their neighbors. And when you disclose classified information, classified conversations that you have access to, it is an act of treason,” he said on PBS Newshour Wednesday.

“He or she should be held to answer for that and treated as any treasonous person would be,” he said.

The Justice Department on Wednesday did not want to tip its hand on what it is doing to uncover the leaks, but pointed to prior statements made by Attorney General Jeff Sessions.

“I expect we’ll get to the bottom of some of this,” Sessions told Fox News in March. “It’ll probably take some convictions to put an end to it.”