Gibraltar border queues 'necessary'
15 August 2013 Last updated at 12:16 BST
Spain has tightened its border controls with Gibraltar, prompting the UK to threaten legal action.
The Spanish government has said the row would not be resolved until a new artificial reef, installed by the Gibraltarians, was removed from the waters off the British territory.
The BBC's Tom Burridge reports from the queues at the Spain/Gibraltar border.