It is the moniker that has stuck to Sir Michael Wilshaw throughout his five years as Ofsted chief inspector.

Now, on his final day in charge, he has uttered the immortal words that helped make Clint Eastwood’s tough-talking, no-nonsense cop Dirty Harry a movie icon.

Before joining Ofsted, Sir Michael told headteachers in an after-dinner speech that some principals going into challenging schools had to be like the San Francisco police inspector.

And weeks before taking up his Ofsted role in 2012, he told MPs that “occasionally I’ve been known to be a bit like Dirty Harry”.

For many, the legend became fact during the subsequent five years, when his outspoken views angered teachers, unions and ministers at different points.

However, after reading out Dirty Harry’s famous “Do you feel lucky, punk?” monologue on BBC Radio 5 Live today, he suggested he may now regret his original remarks.

“I’ve often been misquoted,” he said. “It’s a talk I gave, well before I went into Ofsted, to headteachers to say ‘you go into a tough school, often you’re on your own, and you’ve got to fight the good fight on your own because you’re going to find all sorts of problems, the senior team might be poor, you’ve got to be a bit like Dirty Harry or Clint Eastwood’.

“If I’d known I was going to go into Ofsted, I probably would not have made that speech.”