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Congressional sources tell Fox News that former acting CIA director Michael Morell can expect aggressive questioning over his alleged conflicting statements to Capitol Hill over Benghazi when he testifies on Wednesday.

Morell will face the House Intelligence Committee on Wednesday morning, testifying publicly for the first time on the attacks. Fox News is told that Morell will be pressed to reconcile his past actions and statements to lawmakers in both the House and Senate or potentially face perjury accusations.

One of the allegations, first reported by Fox News in February based on the findings of a Senate Intelligence Committee report on Benghazi, is that Morell seemed to dismiss or downplay the reporting of the CIA's top officer on the ground in Libya, known as the chief of station -- who said there was no protest before the attack.

As Fox News first reported, based on a source with first-hand knowledge of events, as early as two days after the attack the chief of station understood from headquarters the burden was on him to prove a negative – in other words, to prove there was no protest.

One day before then-U.N. ambassador Susan Rice's controversial Sunday show appearances in 2012, where she blamed the attack on a demonstration,the CIA chief of station also wrote an email to Morell and others within CIA leadership, saying the attacks were "not/not an escalation of protests."

Former intelligence officials say Morell must now explain what overwhelming and conclusive evidence he possessed that allowed him to override U.S. personnel on the ground in Libya, including the CIA's top officer, who did not report a protest. The chief of station’s assessment in most every case – apparently, except Benghazi -- is considered gospel.

"This appears to be a matter of -- we're telling you politically we're reaching a different judgment, and now putting you in a position of having to disprove that, " CIA veteran Charles S. Faddis told Fox News."For people in the field, all in the field, all of this is incredibly disheartening."

On Tuesday, the chief of station testified for the first time before a closed House subcommittee hearing on Benghazi -- his critical testimony coming hours before Morell was to be sworn under oath.

A source familiar with his appearance told Fox News the hearing lasted about 90 minutes.

Lawmakers were told the CIA's top officer on the ground in Libya reported throughout the first week there was no protest.

On Wednesday, Morell must also reconcile statements about three key episodes and why he seemed to obfuscate his involvement, though emails released by the administration show he personally cut half the text in the so-called “talking points,” which were the basis for Rice’s flawed explanation of the attack.

In November 2012, the House Intelligence Committee asked a panel of witnesses -- including Director of National Intelligence James Clapper, the head of the National Counterterrorism Center Matt Olsen, and Morell -- who was behind the talking points. Congressional sources say Morell remained silent as his boss, Clapper, said he had no idea.

Later that month, Morell went to Capitol Hill with Rice and met with Republican Sens. Kelly Ayotte, John McCain and Lindsey Graham, who say Morell blamed the FBI for major changes to the talking points.The senators say the FBI went ballistic when they heard Morell was blaming the bureau.

Further, Republican senators on the intelligence committee accuse Morell of misleading them, by stating the talking points were provided to the White House for their awareness and not for their input -- when the email trail later released by the administration showed the opposite, and that administration involvement from the White House and State Department began at the earliest possible stages.

Legal analysts and former government officials say Morell's statements to Ayotte, McCain and Graham, though not in a formal setting, may be a violation of Title 18 Section 1001, which prohibits false statements to investigators,including lawmakers who are exercising an oversight function.

"If you are a witness or someone who is spoken to by federal investigators or senators as part of an investigation -- even if you're not in formal hearing … you still could be subject to the perjury trap,” former deputy assistant attorney generalTom Dupree explained.

Dupree said Morell's testimony Wednesday is "an opportunity to set the record straight, to clear the air, to dispel any of the confusions or misconceptions that arose from his prior testimony.”

He added: “There's been a lot of talk about whether he was totally forthright, whether he may have shaded the facts a little bit in his favor. All of that -- this is his chance to clear the air, start afresh, to basically come clean and say, ‘Look, here's what happened. I'm here today to tell the full truth and nothing but the truth’."

Former Attorney General Michael Mukasey, who is taking a keen interest in Morell’s testimony, broke it down this way for Fox News: "I think Michael Morell should be made to answer questions along two lines of inquiry.One has to do with why he changed the talking points the government was to use ... and instead substitute an account that was politically appealing to the White House but that was contradicted by his own people on the ground. … This would include who he spoke to at the White House and what they told him, and the timing of those conversations."

Mukasey also said Morell should be asked to explain his post-CIA career decisions which closely align him with former Secretary of State Hillary Clinton's aides. After retiring from the CIA, Morell joined Beacon Global Strategies as a counselor.Fox News was first to report on the connections between Beacon’s founding partners, Morell, Clinton and the House Intelligence Committee.

No firm would appear to know more about Benghazi and the administration’s response, while having a vested interest in the scandal's outcome and impact on Clinton's possible presidential ambitions.

Mukasey said the second line of inquiry “has to do with when [Morell] first had contact with Beacon Global Strategies, where he works now, one of whose principals is the former staff director of (House Intelligence Committee) HPSCI."

One of Morell’s new bosses is Michael Allen, the committee’s former staff director. Critics charge that Allen left the Hill and went into business with the people he was once investigating.

"This is a real test for the committee’s oversight function,"Mukasey said.