French border police have accused the U.K. Port of Dover of failing to prepare properly for the rush of passengers that began March 31 when schools closed for the Easter holidays, when many travelers encountered lengthy delays. BBC News reports that some coaches of school children waited for 14 hours to pass through border control, and board ferries to France.

A spokesperson for the French border control said every booth was staffed "continuously." The person said the problems arose on "the British side."

A spokesperson for the French Police Nationale communication team there were problems with the structural organization of the control lines at the port of Dover, on the British side. "The management of the Port of Dover therefore knew in advance that the flow would be a problem," they added.

The chief executive of the Port of Dover, Doug Bannister, earlier told the BBC that new measures have been brought in to manage the flow, and he was confident it could cope with busy periods in future.

Asked whether the additional passport checks because of Brexit had contributed to delays, Bannister had added: "There's no doubt that transiting through borders takes longer now, no doubt about that, since we left the EU.