In cases where there are unanticipated demands for legal services or where there are insufficient funds on hand or available for payment through the legal services revolving fund or in other cases of necessity, the attorney general may request payment for legal services directly from agencies for whom the services are performed to the extent that revenues or other funds are available. Upon approval by the director of financial management the agency shall make the requested payment. The payment may be made on either an advance or reimbursable basis as approved by the director of financial management.