[2008] EWHC 520 (Comm), 1 April 2008. Considers whether an insurance broker was barred from complaints against another by estoppel, and whether excess insurers should be included as defendants. The claimant property company (D) was facing claims for negligence or possible mortgage fraud over valuations. D's excess insurers (M) stated their PII cover did not extend to property valuations. D instigated proceedings against their brokers (H), who had instructed a Lloyd's broker (F) to place the cover. H argued that F was therefore culpable. F argued that H was estopped from such complaint as they had approved the insurance slip, applied for the case against it to be struck out. H further argued that the valuation was included in the policy by construction, or alternatively that the policy should be amended retroactively. H applied for M be added to the claim as defendants under the Civil Procedure Rules 1998 rule 19.2. "Held": The court have power to add M as a defendant using rule 19.2, in the absence of a Part 20 claim. However it was unnecessary as the relevant action was not yet clear, and H could instigate proceedings against M if this became necessary. D could reasonably make claim against H who in turn was not estopped from complaints against F's placing of the insurance. Applications refused.