Gillian Keegan said she would have “probably punched” rude Ofsted staff as she spoke at the Association of School and College Leaders annual conference on Friday, 8 March.
The education secretary appeared to shock Q&A host Pepe Di’Iasio with a frank admission about a “fantastic” school she had recently visited.
Ms Keegan said: “They told me how their Ofsted experience had gone and I was shocked. I was actually shocked.
“I thought: God if I had met these people, I would have probably punched them. They were really rude.”
Mike Short, head of education at Unison, said: “To suggest punching people is an appropriate reaction is not becoming of a government minister.”