The meaning of the broking term 'like-for-like cover' is set to come under scrutiny in a forthcoming legal case.
The case involving CGNU, now Norwich Union, could have far-reaching implications for brokers, who will often compare two policies on a 'like-for-like' basis.
The precise legal definition of the term is not clear, potentially leaving brokers open to professional negligence claims from clients.
James Bateson, a partner at law firm Norton Rose, which is not involved in the case, said there was considerable scope for legal argument over what the term 'like-for-like' cover means.
"The term could relate to such things as wording, attachment point, excess and reinsurance security. It is a legal minefield."
He added: "[The case] is symptomatic of the brave new world in which brokers are finding themselves. There will be an increasing trend for historic practices to be tested before the courts."
A spokesman for CMS Cameron McKenna confirmed that the firm was acting for one of the parties.
He declined to comment on the details of the case, but said it was set to go to trial later this year, with a decision expected in January.