Chris BrightControversy over top London firms’ notoriously flexible stance on conflicts of interest is mounting following a series of high-profile deals that have this year seen UK firms apparently breach local bar rules.

One major firm, Allen & Overy (A&O), has controversially emerged as an adviser to more than one party in three separate instructions this year: the insolvency of TXU, advertising giant WPP’s bid for Cordiant and the on-going battle to control UK supermarket group Safeway.