The Guardian’s assistant editor Michael White last night accused a senior civil servant of being a “pit bull” who was pursuing a “personal vendetta” against his newspaper.

Director of Communications at the Department for Work and Pensions Richard Caseby wrote a guest blog in Press Gazette yesterday attacking The Guardian’s accuracy when it comes to coverage of his department.

Former Sun and Sunday Times managing editor Caseby said: "Why is it that the national newspaper which devotes the most coverage to welfare reform reports on it with such pinpoint inaccuracy?"