Sovereign recently told its adviser force that to compete with its products lower premium rates on the Warehouse website, they could reduce their commission and pass the saving on to the client - known as variable commission.

"Forcing advisers to reduce their commissions down from the standard offering in order to compete with their own direct offering is not something Partners Life intends to do to our advisers."

"We want our clients to be well advised, well serviced and well supported at claims time so we pay the commissions that we think will attract and retain quality advisers," she said.

"If the insurer doesn't believe that their standard commission is appropriate for the work their advisers do then they should change their offering and allow advisers to make informed decisions about whether to support that company or not."

Fidelity Life chief executive Milton Jennings said some of the websites that sell their products do so on a reduced commission, enabling them to offer cheaper premiums.

He said that they offer advisers "tonnes of variety" around commission, but that he believed the advice proposition was about more than premium costs.

"Most of them [advisers] shouldn't be competing on price but service and the advice they give."

AIA head of distribution Darrin Franks said that while relatively rare, advisers did opt for variable commission on occasion.

"The ones [advisers] that can't demonstrate the value for the commission they earn may do," he said.