(CNN) At a time when most State Department staff weren't allowed to travel for work and some weren't even allowed to use their work phones, Secretary of State Mike Pompeo's wife Susan embarked on an eight-day trip with her husband, requiring unpaid staffers to prepare and support her across the Middle East.

Many diplomats, already demoralized by the partial government shutdown, were angry, according to multiple sources familiar with the situation.

"Eyebrows were raised from the start, from the planning, on why is she coming, and why is she coming during the shutdown?" one person familiar with the matter told CNN.

A senior State Department official said "This is BS. You don't bring more people that need staffing, transportation, etc. when embassy employees are working without being paid."

It was Susan Pompeo's presence on the trip at a time State Department staff are working without pay that seemed to cause the furor. There are also questions over whether the use of State Department staffers' time to assist her violated federal regulations.

A 'working trip'

The secretary described it as a "working trip" for her -- telling reporters she joined him to try to help the department "be better."

"So she meets with the medical officers. She'll tour housing. She will write up her thoughts and comments after that. And I wish I had time to do each of those things myself, but she is a force multiplier," he said.

The State Department says most diplomats abroad have not been paid during the shutdown. Sources said many had to come to work anyway to handle this trip -- for some requiring very long hours. It's unclear exactly how many people on the Pompeo trip were not being paid.

According to three people familiar, Susan Pompeo was assigned a control officer who worked exclusively with her. That person was on call for weeks, the sources said, and at each of the stops, Susan Pompeo had her own staffer and her own security personnel.

Furloughed, unpaid State department employees in the various overseas embassies were called in to support the trip by the secretary of state, because his travels are considered a high priority.

Two sources familiar with the situation said that at one of the stops, a staffer and security were tasked with taking Susan Pompeo to the local market and shopping with her -- an activity which caused a delay of about 35 minutes in departure to the next stop, they said.

"They felt like fools, since nearly everyone was working -- working around the clock -- but not being paid! And then they felt even more like fools," one person familiar said.

Another source with knowledge of the trip said people "far and wide across the embassies" were "outraged" at being given these additional responsibilities during the shutdown.

'No one's pleased'

"No one's pleased," the source said. "There's no appreciation for what everyone is doing. No acknowledgment. This is real."

Walter Shaub, the former director of the Office of Government Ethics, said the use of agency staff could violate conduct regulations.

"It's not clear if she has any real authority, but if Secretary Pompeo were, for instance, letting her commandeer departmental staff to assist her with her activities, that would be a misuse of a position that could run afoul of the standards of conduct regulations," he told CNN.

According to the Code of Federal Regulations, a federal employee "shall not encourage, direct, coerce, or request a subordinate to use official time to perform activities other than those required in the performance of official duties or authorized in accordance with law or regulation."

But it's a gray area and according to Retired Rear Adm. John Kirby, a CNN Military & Diplomatic Analyst and a former State Department spokesperson under former President Barack Obama, it is not unusual for secretaries' spouses to travel with them overseas.

"It is not unusual -- and frankly it can be quite beneficial -- to advancing American interests for the spouse of a cabinet secretary to occasionally travel with him or her. The spouse often engages in separate encounters during such trips meeting with local officials and participating in cultural or educational engagements that flesh out and help inform America's foreign policy," Kirby told CNN.

However, Kirby noted that "such accompaniment should not be the norm."

"Care must be taken at all times to ensure meaningful context is gleaned by the cabinet official from the spouse's interactions and that the taxpayer is properly served for the expenditure of such travel," Kirby said.

Brett Bruen, who served in the Obama White House as director of global engagement, told CNN, "During the shutdown to add more complexity and demands on our embassies, with separate movements and programs for Mrs Pompeo, drains limited resources. The only function or diplomats not furloughed are performing is to care for the safety of Americans overseas and national security issues. Why is now the right time to take away time and funds from those essential operations?"

During the trip, Secretary Pompeo noted that Susan Pompeo had met with some of his counterpart's spouses, visited with the families of embassy staff, medical personnel and security staff, and toured housing.

"Frankly, (she's) working to say, 'Are our officers living in the conditions that the Pompeo family would be willing to accept? What are their lives like?' " Secretary Pompeo explained.

Shaub told CNN that if State Department employees are being directed to "sit down and consider" these notes, "that could in some circumstances similarly implicate the misuse of position rules."

"Whether an actionable violation occurs really depends on the degree to which he is using federal resources or staff," Shaub said.

The State Department has not responded to CNN's questions about details of Susan Pompeo's part of the trip -- including how many people were tasked with working with her at each of the stops, how much of the trip's cost she would reimburse or how whatever recommendations she makes would be handled.

At the start of the trip, a State Department spokesperson said her travel would meet all State Department regulations.

Once this story published, however, State spokesperson Robert Palladino said he would not characterize a stop that Susan Pompeo made in Bahrain as a shopping trip, though that is how two sources described it to CNN. He told CNN that she was at a marketplace, but he described it as a meeting -- with the King of Bahrain's wife.

Palladino added: "Mrs. Pompeo traveled with the Secretary on the Middle East trip to be an advocate for State Department families. The Secretary and Mrs. Pompeo know that overseas postings can be challenging for our diplomats and their families."

Similar role at CIA

played a similar role when he served as CIA director. However, Susan Pompeo also Secretary Pompeo said his wifeplayed a similar role when he served as CIA director. However, Susan Pompeo also came under scrutiny for her active role there. Seven sources with knowledge of the matter told CNN in March 2018 that Susan Pompeo regularly spent her days at the agency, traveled with her husband, and attended agency social events. While her husband was there, she served as the "Honorary Chair" of the Family Advisory Board, which serves as a liaison between the agencies and families.

Kathleen Clark, a government ethics expert at the Washington University in St. Louis, told CNN at the time that Susan Pompeo's role at the CIA was a "red flag," and questioned her use of the agency's office space and the assistance she received from CIA officials.

"If staff are helping her, it sounds like she can direct staff. It's odd that someone who is not a government official or an employee is allowed to direct actual government employees," Clark said.