Regional brokers have lashed out at two London market trade bodies which called on the FSA to make full commission disclosure mandatory this week.
The outcry follows a survey conducted on behalf of the International Underwriting Association (IUA) and the Lloyd's Market Association (LMA) which found the majority of corporate insurance buyers wanted full commission disclosure.
But brokers railed against the findings as self-serving and contrary to common sense.
The survey found that more than two thirds of clients said they should know the total income their broker received from placing and handling their company's insurance requirements.
Buyers also underestimated the amount of commission earned by brokers, estimating about half the true figure.
Andrew Kendrick, chairman of the LMA said: "Commercial customers firmly believe that full transparency is the right solution to broker remuneration.
"Mandatory disclosure of broker commissions is the right way forward and will enable the market to operate competitively."
But Biba chief executive Eric Galbraith said the London market's demands were "non-sensical".
He said: "I don't believe the LMA's motives are anything to do with the customer. They have suggested this to put the squeeze on brokers."
Biba's own survey of insurance buyers, he added, had revealed "no demand" for full disclosure.
The LMA and IUA, he said, had "extrapolated results from the survey" to support its own demands.
Chris Blackham, chief executive of Layton Blackham, added: "The IUA spoke to mid to large-sized companies, which are not representative of the UK retail market."
Stuart Alexander chief executive Stuart Reid warned of dire economic consequences for a full disclosure market.
He said: "This is a non-issue and if pursed we are in danger of making it as uneconomic for the general insurance market as it is for the life and pensions market."