The minority members (Democrats) of the House Intelligence Committee, ie the legislative branch, submitted a 10-page memo for declassification by the executive branch. The comensurate process involves the National Security Council, Office of Legal Counsel and all executive agencies within the national security apparatus (CIA, NSA, ODNI, State Dept., DoD, FBI, DOJ) to review the request prior to declassification approval.
Apparently the U.S. Department of Justice, National Security Division, do not approve of the current submission without redactions. WH response letter:


