Motor insurer Admiral's profits could be damaged by any ban placed on the referral fees collected by insurers from personal injury lawyers, The Telegraph reported.

The FTSE 100 insurer, which made a pre-tax profit of £275.9m in its UK motor business in 2010 despite the market suffering heavy losses, attributed 52% (£142.4m) of the full year profit to "ancillary" sales.

Analysts have estimated that a significant proportion of these were from so-called "acceptance fees", which have been widely criticised by leading figures, including former justice secretary Jack Straw.

One industry expert warned that Admiral's model was "not sustainable", adding that the stock market seemed "oblivious" about the issue, the paper reported.

In response, a spokesman for Admiral said: "When one of our customers calls us for help with a claim that was not their fault, we refer them on to a retained accident management company who help sort out their claim, but only if they give us their permission.

"If they don't want to be passed through to our accident management company we do not put them through. If the claim needs to be referred to a lawyer then the accident management company will pay us a referral fee."

Last week, AXA became the first UK insurer to refuse referral fees.