According to Reuters, a “factional” debate is under way within the Trump administration over adding the Muslim Brotherhood to the State Department and Treasury lists of foreign terrorist organizations.

This is a measure often called for by such critics of the Brotherhood as Center for Security Policy President Frank Gaffney, who once again recommended an official terrorist designation on Wednesday’s edition of Breitbart News Daily.

A source in the Trump transition team told Reuters the effort to so designate the Muslim Brotherhood is led by National Security Adviser Michael Flynn. The source was personally in agreement with Flynn.

In Congress, a bill to add the Muslim Brotherhood to the official terrorist list was introduced this month by Sen. Ted Cruz (R-TX) and Rep. Mario Diaz-Balart (R-FL). Secretary of State nominee Rex Tillerson denounced the MB as an “agent of radical Islam” during his confirmation hearings, but he has not made public statements regarding adding them to the foreign terrorist organization list.

However, other Trump advisers, and members of the intelligence and law-enforcement communities, argue the Brotherhood has “evolved peacefully in some countries,” Reuters claims.

They also expressed the pragmatic concern that going hard on the Muslim Brotherhood could complicate diplomatic relations with nations such as Turkey. It would unquestionably, however, please such U.S. allies as Egypt, the United Arab Emirates, and Saudi Arabia, although there have been signs the Saudis might be softening on the Brotherhood as they search for allies against ISIS and Iran.

One official familiar with the State Department’s deliberations conceded that the Muslim Brotherhood’s ideology has influenced such terrorist groups as Hamas, but since it is a large, loose organization spread over several nations, it could be legally difficult to apply the terrorist designation. Allied nations such as Britain have also expressed suspicions about the Brotherhood’s influence, while stopping short of a formal terrorist designation.

Haaretz cites Muslim-American groups who worry that a terrorist designation for the Muslim Brotherhood could be used as a pretext for investigations or punitive actions against them. Unsurprisingly, the Council on American-Islamic Relations (CAIR) is quoted to that effect. CAIR itself has been declared a terrorist organization by the United Arab Emirates and was named by federal prosecutors as an unindicted co-conspirator in a Hamas-funding operation.

Also expressing concerns to Haaretz are diplomats and strategists who note there are significant legal consequences to an FTO designation, and since the Brotherhood has a large membership across several Middle Eastern countries, the number of useful diplomatic and security contacts for the United States would be dramatically reduced.

Dr. Eric Trager of the Washington Institute for Near East Policy called the Muslim Brotherhood a “totalitarian cult that seeks to implement its highly politicized interpretation of Islam, with the ultimate goal of establishing a global Islamic state that will challenge the West,” and told Haaretz the Obama Administration had alienated key partners in the Middle East by engaging with it.

Then again, even with this stern criticism on the table, Trager said a terrorist designation for the MB should be considered carefully, because it would limit America’s options for dealing with important groups in the Brotherhood’s orbit. He offered the Ennahda Party of Tunisia as an example.

The Lawfare blog posted an extensive review of the relevant statutes and argued that designating the Brotherhood in its entirety as a FTO would be illegal, because it is “too diffuse and diverse to characterize,” and not all of its elements are demonstrably interested in terrorist activity.

Crucially, this analysis contends that the economic ties between various chapters of the Brotherhood are not strong enough to make a legal case that the more acceptable segments of the MB are providing material support to the terrorist groups. This would make it difficult to prove that the Brotherhood as a whole supports terrorism.