Jack-in-office

But a man gifted with original thoughts and the power of expressing them, appears to be regarded by everyone in authority as much worse than the worst criminal, and all the 'jacks-in-office' unite to kick him to death if they can.

Source: wiktionary

1967, C. P. Snow, foreword to A Mathematician's Apology, G. H. Hardy, 1948. Chapel at Trinity was compulsory. Hardy told the Dean, …, that he could not conscientiously attend. The Dean, who must have been a jack-in-office, insisted that Hardy should write to his parents and tell them so.

Source: wiktionary