The Technical Committee has a number of working sub-committees (detailed here). All committee members are experts in their own fields. The sub-committees are all heavily involved in consultation with Government, in public and private, on proposed tax legislation. An important example of this is the thorough line-by-line review in the limited time while the Finance Bill is before Parliament.
Weaknesses and anomalies in legislation and drafting are identified (not infrequently by members in their practices who notify the Institute) and representations are made appropriately.