President Donald Trump's son-in-law Jared Kushner has reportedly been behind a plan to get Secretary of State Rex Tillerson fired.

The two apparently have been "clashing heads since day one."

A number of high profile shakeups in Trump's cabinent are reportedly in the works, with Kushner pulling the strings on many of them.

A plan to oust Secretary of State Rex Tillerson from his Cabinet-level post was orchestrated in part by President Trump's son-in-law Jared Kushner, according to multiple sources, one of whom said the two senior administration officials have "been clashing heads since day one."

White House officials reportedly confirmed Thursday that there are high-level discussions taking place about replacing Tillerson with CIA Director Mike Pompeo, whose own position would be filled by Arkansas Sen. Tom Cotton.

Both men have developed close relationships with Trump and appear to be on board with the plan, a former White House aide told the Washington Examiner.

"The initial narrative had focused on [United Nations Ambassador Nikki] Haley going over to the State Department, but Pompeo has continued to increase his influence within the administration over the last several months," the aide said.

Trump even considered Pompeo seriously as a candidate for chief of staff after he decided to replace his first pick for that role, Reince Priebus. Sources close to the White House have long described the relationship between Trump and Pompeo as warm and productive.

"The thing about Pompeo is he spends so much of his day with the president, talking about intelligence and international affairs," said the former White House aide.

The former Kansas congressman has also demonstrated a willingness to wade into politics to shield his boss during rocky moments. In early August, for example, Pompeo was one of the few administration officials who readily defended Trump on Sunday talk shows amid a firestorm over the president's reaction to racial violence in Charlottesville, Va.

Tillerson, on the other hand, said Trump only "speaks for himself" on the issue of white nationalism, a comment that was widely interpreted as a repudiation of Trump's decision to condemn "both sides" for a neo-Nazi rally that spun out of control and claimed the life of an anti-racist protester.

Rex Tillerson and Donald Trump. Mark Wilson/Getty Images

Trump has also pushed back publicly against Tillerson's foreign policy overtures in the past. On North Korea especially, the president and Tillerson have often appeared to pursue completely divergent paths toward curbing the nuclear ambitions of Pyongyang. Tillerson has repeatedly stressed the importance of relying on diplomatic channels to ease tensions with Kim Jong Un's regime, while Trump has made overt threats ranging from ensuring the "total destruction" of the hermit kingdom to petty name-calling of its dictator.

More recently, Trump told Fox News' Laura Ingraham that neither Tillerson nor any other State Department staffers had control of his administration's foreign policy.

"Let me tell you, the one that matters is me," Trump said in response to a question about the lack of appointees at Foggy Bottom. "I'm the only one that matters, because when it comes down to it, that's what the policy is going to be."

The New York Times first reported the major shake-up on Thursday, following months of speculation that Tillerson was headed for the door. The former Exxon Mobil chief was accused in early October of insulting Trump's intelligence by calling him a "moron" during a closed-door meeting with defense officials, a claim he later said was part of "the games of Washington" but repeatedly refused to deny.

But the former White House aide said it was Tillerson's decision last week to avoid sending a senior delegation to India for Ivanka Trump's trip to the annual Global Entrepreneurship Summit that has led Kushner to push hard for the secretary of state's firing.

"There was increasing talk that Rex wasn't going to be on the job for long, but the Ivanka story, that was kind of the last straw. It sort of sealed the deal," the aide said, adding, "This is Jared, 100 percent. [He and Tillerson] have been clashing heads since day one."

A separate White House official said previously that the president's son-in-law was less involved in discussions earlier this fall about whether to recertify the Iran nuclear agreement. Some outlets have reported that Kushner's portfolio has gradually shrunk since chief of staff John Kelly took the reins from Priebus in July and immediately sought to impose order in the West Wing.

"There is no plan so therefore there is nothing for him to push," insisted another White House official, in reference to Kushner. Some reports have credited Kelly with developing the transition plan for moving on from Tillerson.

Sources involved in the Iran deal deliberations at the time said Trump expressed a strong desire to fulfill a campaign promise by scrapping the deal, while Tillerson advocated internally to preserve the deal in order to avoid straining relationships with key U.S. allies. The debate, which took place over many weeks, put Tillerson at odds with Haley, a Cabinet rival whose star power on the international stage has threatened to eclipse his own.

Haley, a favorite of Trump's, was the most vocal administration official when it came to criticism of the Joint Comprehensive Plan of Action, as the Iran deal is formally known. Trump ultimately decided to set in motion a plan that could lead to the end of the JCPOA against Tillerson's wishes.

Candidate Donald Trump speaks at the 'Stop the Iran Deal' rally in Washington D.C. in September 2015. Susan Walsh/AP

The former White House aide said Haley, who dismissed rumors in mid-October about replacing Tillerson in the event he was fired, is "in no hurry" to take over the agency.

"She may not be the one now, but she's first in line the next time around," the aide said.

As challenges on the global stage have grown larger in scope and intensity — such as the rapidly-nuclearizing North Korean regime, Russia's scramble to dictate the terms of the Syrian peace process, and a humanitarian crisis in Yemen — Tillerson's most visible accomplishment as the nation's chief diplomat has been making changes to the internal structure of the State Department.

Meanwhile, Haley has delivered a string of fierce performances at the U.N. Security Council, Kushner has assumed responsibility for brokering a peace deal in the Middle East, and Ivanka Trump has often received more attention for her largely symbolic trips overseas than Tillerson has for his official travels.