Having lasted just 32 working days before quitting as chairman of Lazard International, Naguib Kheraj has made a stunning return to his old firm Barclays to serve as a part-time adviser.

When announcing the end of his short-lived stint at Lazard in February, the 46-year-old said he had "underestimated" the difficulty of combining his philanthropic commitments with being a full-time employee of the independent advisory firm.