Children are being denied the chance to develop “resilience and grit” because of schools’ over-zealous health and safety policies, the chief inspector of schools says.

Amanda Spielman said schools must stop trying “to wrap them in cotton wool” because it leaves them ill-prepared for the challenges of later life.

Schools had to do more to “distinguish between real and imagined risk”, she said, adding that Ofsted will now train its inspectors to ensure schools are not rewarded for overbearing policies.

Ms Spielman, who took over as chief inspector in March, said children must stop being forced to wear hi-vis jackets on school trips “like troupes of mini-construction workers minus the hard hats”.

Writing in the Sunday Telegraph, Ms Spielman said an “over-cautious culture has developed in our schools” that was holding back children and limiting their experiences.

This “deprives children of rewarding experiences, of the opportunity to develop resilience and grit and which makes it hard for them to cope with normal everyday risk”.

Ms Spielman cited examples of school teachers popping children’s balloons and throwing them away because they were dangerous. In another case a sports day was cancelled because of “dew on the grass”.