"It is in response to the Children's Commissioner's report that said significant numbers of young people are at risk of being exploited.
"I think (the risk) has always been there but we have not been as aware of it as we are now."
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One professor warns of a 'potentially disastrous capacity crunch'.
A number of families were on board the service from London Euston to Stoke. One family left the train early to escape the abuse.
She's called Amy, and was visiting a hospital.