Insurers could face a potential bill for £100m a year if the government goes ahead with controversial plans to recover hospital treatment costs.

A report from the Bar Council has endorsed proposals published by the Law Commission last year that favour the extension of the NHS's powers to recover treatment costs from motor insurers.

Barristers' leaders said the NHS should have the same powers as private health companies to bill insurers for treating motor accident victims.

The NHS and local authorities were omitted from a law introduced last November, that allowed motor accident victims to bill those liable for their treatment costs.

But the Bar Council said this loophole should be closed.

If granted, these new powers could save the taxpayer up to £100m a year, the Bar Council estimates, with most of the charge transferring to insurers.

Matt Kelly QC, the report's author, said: "Millions of pounds of taxpayers money are spent each year on treating people who have suffered as a result of someone's negligence. Why should the public pay?"

A spokesman for the NHS Confederation said the proposal could potentially become an important source of funding but added that the billing process would need to be keptsimple.

However, the ABI fears these added powers could be applied to other types of insurer such as public and employer liability specialists.

An ABI spokesman said: "It is difficult to argue in legal terms that there should be any difference between a motor accident or any other type of public liability accident."

He added that any proposed law change should not be retrospective and that it should be subject to thorough consultation with insurers.