Britain's leading employers are asking their staff if they went to public school as part of a Government drive to improve diversity in the workforce, The Telegraph can disclose.

Ministers have published a series of socio-economic questions for staff about their backgrounds intended for use by major companies and the Civil Service.

They include asking staff whether they attended a fee paying school, what their parents did for a living, whether they qualified for free school meals as children and their parents’ academic qualifications. A fifth optional question asks whether they consider themselves to be working class.

Critics said the questions were “naïve”, “totalitarian”, and could lead to “socio-economic cleansing” and a “purge of middle class staff” in offices across the UK.

Tens of thousands of civil servants will be asked the questions in the Civil Service’s annual “people survey” in October this year.