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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Ann Myatt, who is contesting Jo Cox's former seat, told a hustings: "We've not yet shot anybody so that's wonderful."
The 26-year-old said she was moving on to the "next big chapter" - which includes a new show about her venture into motherhood.
Patchy rain will affect many northern areas of the UK over the next 24 hours.