John Kay, who this year authored a review of the UK equity markets, has told the Parliamentary Commission on Banking Standards that “ringfencing” retail and investment banking operations would prove difficult, and would not get to the bottom of the industry’s culture problems.

The Commission was set up earlier this year to investigate professional standards in the UK banking sector, with particular reference to the Libor rate-rigging controversy. It aims to make recommendations to the government on regulatory changes and has heard from a number of high-profile industry figures including Paul Volcker, Erkki Liikanen and Martin Wheatley.