An arrangement whereby cost draftsmen were retained by solicitors on the basis that their payment was dependent upon costs being recovered from a liable party on a detailed costs assessment infringed the indemnity principle and made such costs irrecoverable. In the circumstances, the draftsmen had a right of audience before the Supreme Court Costs Office for a detailed costs assessment hearing as the arrangement between them and the instructing solicitors was not a nullity in law even though it was unenforceable against a liable party.