A spokesman for the ABI said the body is writing to Osborne asking for a 'completely independent' investigation into how the Financial Conduct Authority handled disclosure of a planned review of the industry.

Shares in top insurers fell sharply on Friday after a newspaper interview with a senior FCA supervisor prompted speculation the probe could lead to changes that would affect the profitability of their products.

The regulator clarified its position in a statement early on Friday afternoon, almost six and a half hours after shares started trading.

"The ABI is writing to the Chancellor. The events of last week were very serious and we believe the investigation into the regulator needs to be completely independent. The regulator cannot investigate itself," an ABI spokesman said.

(Reporting by Chris Vellacott. Editing by Steve Slater)

By Chris Vellacott