Biba has voiced concerns over the prospect of brokers being forced to work a maximum 48-hour week.
Biba's head of technical services, Peter Staddon, said he was concerned that the European Working Time Directive - which would impose a 48-hour working week on employees - would erode broker productivity.
His comments came as the CBI renewed its call for Britain to opt out of the Directive.
Staddon said: "Many brokerages have opted out of the Directive. Brokers have a difficult job to do and inevitably need to often work at least 50 hours a week.
"If you are going to bring this in, then it would be better to do it selectively and target sectors, such as the medical profession, where it would bring clear benefits."
With the European Commission set to debate the issue later in the year, the CBI has published research, which revealed that the directive could have a "significant or severe" impact on business.
CBI director general Digby Jones said: "Further restrictions on working time would be a kick in the teeth for many firms, particularly smaller ones."
The CBI's stance is in direct opposition to the unions. TUC general secretary Brendan Barber said: "Working long hours can lead to unnecessary stress and people with excessive days are more likely to have accidents at work.
"Most European countries have set their working time limits below 48 hours, and the UK is the only EU country still with an opt-out.
"The government must stand firm against this employer onslaught and act to stop exploitative bosses from squeezing even more out of their overworked staff by refusing to renegotiate another opt-out when the current one expires later this year."
