Republican members of Congress plan a host of questions for Secretary of State Hillary Clinton during her long-awaited testimony on Wednesday about the deadly attack on the U.S. diplomatic compound in Benghazi, Libya.

Questions are expected to range from a security vacuum in Northern Africa to new cables suggesting that Ambassador Christopher Stevens, who was killed in the Sept. 11 assault, once proposed moving the compound to a more secure location adjacent the CIA Annex, sources tell CNN.

The presence on the House Foreign Relations Committee of several new members and on the Senate Foreign Relations Committee of at least two possible GOP presidential hopefuls -- Marco Rubio of Florida and Rand Paul of Kentucky -- has some State Department officials anticipating aggressive questions about whether the presence of Islamic extremists in Mali and Algeria were in any way related to past decisions by the Obama administration to keep U.S. combat troops out of Libya.

Most questions are expected to re-visit well-worn lines of inquiry about why requests by officials on the ground in Libya for additional security were not heeded, and faulty talking points about whether an anti-Islam video played a role in the attack that also killed three other Americans.

But sources tell CNN that congressional staffers have also been shown new State Department e-mails and cables indicating that in November 2011, Stevens, concerned about the safety of the compound in Benghazi, proposed two options to the State Department.

The first involved moving the compound back into a hotel. The second would move the compound to an unoccupied villa adjacent the CIA Annex.

CIA officials agreed with U.S. diplomatic personnel on the ground that the latter option would be safer. But the State Department rejected the idea.

Other questions could involve the State Department response to the terrorist bombing of the U.S. compound in Benghazi that had occurred the previous June.

Lawmakers may also be interested in Clinton's precise whereabouts on the night of the September attack, her personal involvement in administration actions that night as well as efforts to locate Stevens, who went missing before he died.

Clinton will testify for 90 minutes before the Senate Foreign Relations Committee in the morning and 90 minutes before the House Foreign Affairs Committee in the afternoon.

Weak security

Senior officials tell CNN that Clinton will not shy away from any tough questions and intends to assert responsibility for weak security at U.S. diplomatic posts, something that State Department is urgently addressing, senior officials tell CNN.

It's a position Clinton took soon after the September attack, telling CNN in an interview last October that she was ultimately responsible for security.

"I'm in charge of the State Department, 60,000 plus people all over the world, 275 posts. The president and the vice president certainly wouldn't be knowledgeable about specific decisions that are made by security professionals," Clinton said in the interview.

An independent investigation of the incident absolved Clinton of blame for weak security. The probe, instead, placed responsibility in the Benghazi case on working level officials in the offices of Diplomatic Security and Near East Affairs.

The findings of the Accountability Review Board prompted the resignation of the top diplomatic security official. Others have been fired or reassigned.

There have been more than 30 hearings and closed door briefings on Benghazi with State Department officials present.

Clinton's scheduled appearance in December was postponed after she fell ill and then suffered a concussion and a blood clot in December.

Responding to accusations from her harshest critics that Clinton has been avoiding Congress, the officials noted that she was the first top official to brief the full Senate in closed session on Sept. 20.

"Answer every question"