Aid organisations said migrants camped in Calais had made last-ditch attempts to cross the Channel ahead of today's operation.
Border police were said to have spotted groups of up to 40 people hiding in bushes along roads leading to the port.
Some were attempting to jump on lorries as they slowed down.
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The elderly woman's son complained to the council that his mother had been deprived of her liberty in an 'unprecedented' legal case.