The UK parliamentary inquiry into the demise of department store chain BHS and its £571 million pensions deficit is developing into a full-blown row, with Sir Philip Green disputing the Pensions Regulator's version of events – and experts calling for the authority to get tougher.

On May 11, Green's Arcadia Group accused the Pensions Regulator's chief executive, Lesley Titcomb, of getting her facts wrong when she was questioned by the Work and Pensions Select Committee on May 9.