A senior pharmaceutical executive has been forced by the schools inspectorate to resign as a top adviser only one month after he was appointed, in a move likely to damage efforts to bring private expertise to the public sector.

Paul Blackburn, senior vice-president and financial controller at GlaxoSmithKline, was asked to leave his part-time voluntary post as a member of Ofsted’s board of non-executives last weekend despite being appointed amid high praise at the start of June.