Ofsted chief Amanda Spielman has warned that underperforming schools can get caught in a culture of "disadvantage one-upmanship", where schools focus too much on their pupils' deprivation.
She likened it to a Monty Python comedy sketch where people compete with claims to have had the toughest childhood.
Ms Spielman was presenting her annual report, which highlighted a small core of persistently underachieving schools.
But she said disadvantage was not an excuse for low achievement.
The Ofsted chief suggested schools seemed sometimes to…