SUP 5.3 explains the FSA's policy on the use of skilled persons. The FSA will have regard to all relevant factors, including the circumstances of the credit union, the availability of alternative tools and the cost implications for the credit union (which would have to pay for the services of the skilled person).
SUP 5.4 explains the appointment and reporting process. The FSA will send to a credit union a notice requiring it to provide a report by a skilled person, and give written notification of the report's purpose, scope, and timetable. The FSA will normally seek to agree with the credit union in advance which skilled person (whether accountant, lawyer or other person with relevant skills) will make the report.