The Metropolitan Police chief said a campaign launched to identify possible victims of female genital mutilation (FGM) "warns" people of the law.
Sir Bernard Hogan-Howe said: "They have an option to stop - the fact they bought a ticket to me is irrelevant.
"They should not be committing a serious attack on a child and they should not be breaking the law."
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A panel of 11 justices will hear appeals from two separate challenges brought in England and Scotland to the prorogation of Parliament.
The fire broke out on Monday evening.
Vernon Unsworth is suing the billionaire for defamation.