Irregular migration to the UK "is increasing", an anti-trafficking expert said.
Andy Desmond, Director of Anti-Trafficking Consultants, told Good Morning Britain that the hot weather simply makes cases, such as those of migrants in lorries, "more overt because of their own distress."
Following the discovery of 35 Afghan Sikhs in a shipping container at Tilbury Docks at the weekend, a lorry has been discovered carrying 15 migrants with suspected dehydration in Somerset. The German driver has been arrested.
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The UK economy grew by 0.3% during the second quarter of 2017, up from 0.2% in the first three months of the year.