CFAs which comply with the Conditional Fee Agreements Regulations 2000 (SI 2000/692) (CFAR 2000) are enforceable even though the essence of such an agreement is that the client will not have to pay his solicitor any costs if his case is unsuccessful (s 58(3)(c) of the Courts and Legal Services Act (CLSA) 1990. However, now that the success fee and after the event insurance premium are potentially recoverable from the unsuccessful opponent along with the other costs of the proceedings, the paying party frequently seeks to challenge the validity of the CFA on the grounds that it does not comply with CFAR 2000. This is because it is argued that if the CFA is unenforceable against the client then no costs are payable by the party ordered to pay costs due to the operation of the indemnity principle.