At least 13 of the highest paid mandarins and bureaucrats have held second roles during their time in Whitehall, an investigation by The Telegraph has found. Among them is Jonson Cox, the head of the Water Services Regulation Authority (Ofwat) who holds non-executive roles at two energy companies, and Sir Stephen Lovegrove, the UK’s National Security Adviser, who is a non-executive director at a property company. The revelations comes just days after Simon Case, the Cabinet Secretary, ordered all civil servants to reveal their second jobs in the wake of the Greensill lobbying scandal. There is no suggestion that the officials identified by The Telegraph broke any rules, but the extent of the crossover has led to MPs calling for a crackdown on those in the upper echelons of the public sector holding dual roles. Sir Alistair Graham, a former chairman of the Committee on Standards in Public Life, said the findings were “shocking” as he called for senior civil servants to be “banned” from working in the private sector.